US20160032739A1 - Axial flow compressor and gas turbine equipped with axial flow compressor - Google Patents

Axial flow compressor and gas turbine equipped with axial flow compressor Download PDF

Info

Publication number
US20160032739A1
US20160032739A1 US14/813,418 US201514813418A US2016032739A1 US 20160032739 A1 US20160032739 A1 US 20160032739A1 US 201514813418 A US201514813418 A US 201514813418A US 2016032739 A1 US2016032739 A1 US 2016032739A1
Authority
US
United States
Prior art keywords
rotor blade
dovetail
blade dovetail
axial flow
flow compressor
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Abandoned
Application number
US14/813,418
Other languages
English (en)
Inventor
Masaru Sekihara
Yasuo Takahashi
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Mitsubishi Power Ltd
Original Assignee
Mitsubishi Hitachi Power Systems Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Mitsubishi Hitachi Power Systems Ltd filed Critical Mitsubishi Hitachi Power Systems Ltd
Assigned to MITSUBISHI HITACHI POWER SYSTEMS, LTD. reassignment MITSUBISHI HITACHI POWER SYSTEMS, LTD. ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: SEKIHARA, MASARU, TAKAHASHI, YASUO
Publication of US20160032739A1 publication Critical patent/US20160032739A1/en
Abandoned legal-status Critical Current

Links

Images

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01D—NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES
    • F01D5/00—Blades; Blade-carrying members; Heating, heat-insulating, cooling or antivibration means on the blades or the members
    • F01D5/30—Fixing blades to rotors; Blade roots ; Blade spacers
    • F01D5/3007—Fixing blades to rotors; Blade roots ; Blade spacers of axial insertion type
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01D—NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES
    • F01D25/00—Component parts, details, or accessories, not provided for in, or of interest apart from, other groups
    • F01D25/24—Casings; Casing parts, e.g. diaphragms, casing fastenings
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01D—NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES
    • F01D5/00—Blades; Blade-carrying members; Heating, heat-insulating, cooling or antivibration means on the blades or the members
    • F01D5/02—Blade-carrying members, e.g. rotors
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01D—NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES
    • F01D5/00—Blades; Blade-carrying members; Heating, heat-insulating, cooling or antivibration means on the blades or the members
    • F01D5/12—Blades
    • F01D5/14—Form or construction
    • F01D5/147—Construction, i.e. structural features, e.g. of weight-saving hollow blades
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01D—NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES
    • F01D9/00—Stators
    • F01D9/02—Nozzles; Nozzle boxes; Stator blades; Guide conduits, e.g. individual nozzles
    • F01D9/04—Nozzles; Nozzle boxes; Stator blades; Guide conduits, e.g. individual nozzles forming ring or sector
    • F01D9/041—Nozzles; Nozzle boxes; Stator blades; Guide conduits, e.g. individual nozzles forming ring or sector using blades
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02C—GAS-TURBINE PLANTS; AIR INTAKES FOR JET-PROPULSION PLANTS; CONTROLLING FUEL SUPPLY IN AIR-BREATHING JET-PROPULSION PLANTS
    • F02C3/00—Gas-turbine plants characterised by the use of combustion products as the working fluid
    • F02C3/04—Gas-turbine plants characterised by the use of combustion products as the working fluid having a turbine driving a compressor
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
    • F05D—INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS
    • F05D2220/00—Application
    • F05D2220/30—Application in turbines
    • F05D2220/32—Application in turbines in gas turbines
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
    • F05D—INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS
    • F05D2240/00—Components
    • F05D2240/20—Rotors
    • F05D2240/30—Characteristics of rotor blades, i.e. of any element transforming dynamic fluid energy to or from rotational energy and being attached to a rotor
    • F05D2240/301—Cross-sectional characteristics
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
    • F05D—INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS
    • F05D2240/00—Components
    • F05D2240/35—Combustors or associated equipment
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
    • F05D—INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS
    • F05D2250/00—Geometry
    • F05D2250/20—Three-dimensional
    • F05D2250/24—Three-dimensional ellipsoidal
    • F05D2250/241—Three-dimensional ellipsoidal spherical
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
    • F05D—INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS
    • F05D2250/00—Geometry
    • F05D2250/70—Shape
    • F05D2250/71—Shape curved
    • F05D2250/711—Shape curved convex
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
    • F05D—INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS
    • F05D2250/00—Geometry
    • F05D2250/70—Shape
    • F05D2250/71—Shape curved
    • F05D2250/712—Shape curved concave
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
    • F05D—INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS
    • F05D2260/00—Function
    • F05D2260/94—Functionality given by mechanical stress related aspects such as low cycle fatigue [LCF] of high cycle fatigue [HCF]
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
    • F05D—INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS
    • F05D2260/00—Function
    • F05D2260/94—Functionality given by mechanical stress related aspects such as low cycle fatigue [LCF] of high cycle fatigue [HCF]
    • F05D2260/941—Functionality given by mechanical stress related aspects such as low cycle fatigue [LCF] of high cycle fatigue [HCF] particularly aimed at mechanical or thermal stress reduction

Definitions

  • the present invention relates to an axial flow compressor that secures a rotor blade with a wheel dovetail having a certain angle in the direction of a rotational axis, and a gas turbine equipped with the axial flow compressor, and more particularly to an axial flow compressor with a structure in which a rotor blade is secured with a wheel dovetail provided so as to have a certain angle in the direction of the rotational axis of the rotor blade and a gas turbine that includes the axial flow compressor, a combustor to mix compressed air supplied from the axial flow compressor with a fuel and burn a mixture of the compressed air with the fuel to generate a high-temperature combustion gas, and a turbine which is driven by the high-temperature combustion gas supplied from the combustor to generate a rotational power with the combustion gas supplied from the combustor.
  • a gas turbine comprises mainly an axial flow compressor, a combustor, and a turbine.
  • the axial flow compressor intakes an air from the atmosphere and adiabatically compresses the air.
  • the combustor mixes the compressed air supplied from the axial flow compressor with a fuel, and burns a mixture of the compressed air with the fuel to generate a high-temperature combustion gas.
  • the turbine When the combustion gas supplied from the combustor is expanded, the turbine generates a rotational power. An exhaust gas exhausted from the turbine is released to the atmosphere.
  • the rotor blade of the axial flow compressor often has a rotor blade dovetail, which fits to a groove in a dovetail formed on the outer circumferential side of the wheel, on the inner circumferential side of a rotor blade and is secured to the wheel dovetail.
  • fatigue damage One type of damage that must be considered in the dovetail structure is fatigue damage.
  • fatigue damage when excessive stress is repeatedly exerted, a fine crack is initiated from, for example, a metal surface, grows, and causes breakage.
  • An effective countermeasure against this damage is to reduce exerted stress. It is desirable to reduce centrifugal stress or thermal stress by, for example, changing a shape or reducing a thermal load.
  • Japanese Patent Laid-open No. 2008-69781 proposes a structure in which an undercut fillet radius, for a rotor blade dovetail, that has a multi-part profile shape is formed at an intersection of a dovetail platform and a dovetail pressure surface.
  • Japanese Patent Laid-open No. 2008-69781 proposes a structure in which a fillet is provided on the dovetail section.
  • an angle with respect to the direction of a rotational axis tends to increase, and asymmetry of a load exerted from a rotor blade fitting to a groove formed in a wheel dovetail provided on the outer circumferential surface of a conical or cylindrical wheel (asymmetry between a force with which a load exerted from the rotor blade is exerted in the same forward direction as the rotational direction of the rotor blade and a force exerted on the reverse rotational direction, which is opposite to the rotational direction of the rotor blade) tends to increase for each dovetail at both the upstream side and the downstream side in the flow direction of a working fluid.
  • An object of the present invention is to provide an axial flow compressor and a gas turbine equipped with the axial flow compressor, wherein the axial flow compressor includes rotor blade dovetails, each of which reduces high stress exerted on the rotor blade by reducing an uneven contact with the corresponding wheel dovetail so as to level a load that would otherwise become asymmetric between the forward direction and reverse direction of the rotational direction of the rotor blade.
  • An axial flow compressor comprising: a rotor blade and a stator blade to intake air from an atmosphere and compress the air; a wheel to secure the rotor blade; a casing to secure the stator blade; wherein a wheel dovetail which is machined on an outer circumferential surface of the wheel to have a certain angle with respect to a rotational axis of the axial flow compressor; and a rotor blade dovetail which is machined on an inner circumferential side of the rotor blade to secure by being fitted to the wheel dovetail, characterized in that: a cut surface is formed on at least one of an upstream side and a downstream side of the rotor blade dovetail by cutting a part of the rotor blade dovetail in a surface form.
  • a gas turbine of the present invention comprising:
  • an axial flow compressor configured so that the above-described axial flow compressor which is used to intake air from the atmosphere and compress the air; a combustor to mix the compressed air supplied from the axial flow compressor with a fuel, and burn a mixture of the compressed air with the fuel to generate a high-temperature combustion gas; and a turbine which is driven by the high-temperature combustion gas generated in the combustor to generate a rotational power.
  • an axial flow compressor that includes rotor blade dovetails that reduce high stress exerted on rotor blades by reducing an uneven contact with each wheel dovetail so as to level a load that would otherwise become asymmetric between the forward direction and reverse direction of the rotational direction of the rotor blade, and a gas turbine equipped with the axial flow compressor, can be realized.
  • FIG. 1 partially illustrates a rotor blade dovetail that secures a rotor blade included in an axial flow compressor according to a first embodiment of the present invention; the upstream side of the inclined surface of the rotor blade dovetail, the inclined surface being a curved surface, is cut in a planar shape.
  • the drawing at the bottom of FIG. 1 partially illustrates the rotor blade dovetail in this embodiment when viewed from above.
  • FIG. 2 partially illustrates the structure of the axial flow compressor according to the first embodiment of the present invention; in the structure, compressor rotor blades, each of which has the rotor blade dovetail, are incorporated into their relevant wheel dovetails of a compressor wheel.
  • FIG. 3 schematically illustrates the structure of a gas turbine that has the axial flow compressor, having the rotor blade dovetails, according to the first embodiment of the present invention, a combustor, and a turbine.
  • FIG. 4 partially illustrates a rotor blade dovetail that secures a rotor blade included in an axial flow compressor according to a second embodiment of the present invention; the downstream side of the inclined surface of the rotor blade dovetail, the inclined surface being a curved surface, is cut in a planar shape.
  • the drawing at the bottom of FIG. 4 partially illustrates the rotor blade dovetail in this embodiment when viewed from above.
  • FIG. 5 partially illustrates a rotor blade dovetail that secures a rotor blade included in an axial flow compressor according to a third embodiment of the present invention; both the upstream side and the downstream side of the inclined surface of the rotor blade dovetail, the inclined surface being a curved surface, are cut in a planar shape.
  • the drawing at the bottom of FIG. 5 partially illustrates the rotor blade dovetail in this embodiment when viewed from above.
  • FIG. 6 partially illustrates a rotor blade dovetail that secures a rotor blade included in an axial flow compressor according to a fourth embodiment of the present invention; the upstream side of the inclined surface of the rotor blade dovetail, the inclined surface being a curved surface, is cut in a concave shape formed with a spherical surface.
  • the drawing at the bottom of FIG. 6 partially illustrates the rotor blade dovetail in this embodiment when viewed from above.
  • FIG. 7 partially illustrates a rotor blade dovetail that secures a rotor blade included in an axial flow compressor according to a fifth embodiment of the present invention; the upstream side of the inclined surface of the rotor blade dovetail, the inclined surface being a curved surface, is cut in a convex shape formed with a spherical surface.
  • the drawing at the bottom of FIG. 7 partially illustrates the rotor blade dovetail in this embodiment when viewed from above.
  • FIG. 8 partially illustrates a rotor blade dovetail that secures a rotor blade included in an axial flow compressor according to a sixth embodiment of the present invention; the upstream side of the inclined surface of the rotor blade dovetail, the inclined surface being a curved surface, is cut in a concave shape formed with a curved surface.
  • the drawing at the bottom of FIG. 8 partially illustrates the rotor blade dovetail in this embodiment when viewed from above.
  • FIG. 9 partially illustrates a rotor blade dovetail that secures a rotor blade included in an axial flow compressor according to a seventh embodiment of the present invention; the upstream side of the inclined surface of the rotor blade dovetail, the inclined surface being a curved surface, is cut in a convex shape formed with a curved surface.
  • the drawing at the bottom of FIG. 9 partially illustrates the rotor blade dovetail in this embodiment when viewed from above.
  • FIG. 10 partially illustrates a rotor blade dovetail that secures a rotor blade included in an axial flow compressor according to an eighth embodiment of the present invention; the upstream side of the inclined surface of the rotor blade dovetail, the inclined surface being a curved surface, is cut in a concave shape consisting of a plurality of flat surfaces.
  • the drawing at the bottom of FIG. 10 partially illustrates the rotor blade dovetail in this embodiment when viewed from above.
  • FIG. 11 partially illustrates a rotor blade dovetail that secures a rotor blade included in an axial flow compressor according to a ninth embodiment of the present invention; the upstream side of the inclined surface of the rotor blade dovetail, the inclined surface being a curved surface, is cut in a convex shape consisting of a plurality of flat surfaces.
  • the drawing at the bottom of FIG. 11 partially illustrates the rotor blade dovetail in this embodiment when viewed from above.
  • FIG. 12 partially illustrates a rotor blade dovetail that secures a rotor blade included in an axial flow compressor according to a tenth embodiment of the present invention; the upstream side of the inclined surface of the rotor blade dovetail, the inclined surface being a flat surface, is cut in a planar shape.
  • the drawing at the bottom of FIG. 12 partially illustrates the rotor blade dovetail in this embodiment when viewed from above.
  • FIG. 13 partially illustrates a rotor blade dovetail that secures a rotor blade included in an axial flow compressor according to an eleventh embodiment of the present invention; the upstream side of the inclined surface of the rotor blade dovetail, the inclined surface being a flat surface, is cut in a concave shape formed with a curved surface.
  • the drawing at the bottom of FIG. 13 partially illustrates the rotor blade dovetail in this embodiment when viewed from above.
  • FIG. 14 partially illustrates a rotor blade dovetail that secures a rotor blade included in an axial flow compressor according to a twelfth embodiment of the present invention; the upstream side of the inclined surface of the rotor blade dovetail, the inclined surface being a flat surface, is cut in a convex shape formed with a curved surface.
  • the drawing at the bottom of FIG. 14 partially illustrates the rotor blade dovetail in this embodiment when viewed from above.
  • FIG. 15 partially illustrates a rotor blade dovetail that secures a rotor blade included in an axial flow compressor according to a thirteenth embodiment of the present invention; the upstream side of the inclined surface of the rotor blade dovetail, the inclined surface being a flat surface, is cut in a concave shape consisting of a plurality of flat surfaces.
  • the drawing at the bottom of FIG. 15 partially illustrates the rotor blade dovetail in this embodiment when viewed from above.
  • FIG. 16 partially illustrates a rotor blade dovetail that secures a rotor blade included in an axial flow compressor according to a fourteenth embodiment of the present invention; the upstream side of the inclined surface of the rotor blade dovetail, the inclined surface being a flat surface, is cut in a convex shape consisting of a plurality of flat surfaces.
  • the drawing at the bottom of FIG. 16 partially illustrates the rotor blade dovetail in this embodiment when viewed from above.
  • FIG. 17 partially illustrates a rotor blade dovetail that secures a rotor blade included in an axial flow compressor according to a fifteenth embodiment of the present invention; the downstream side of the inclined surface of the rotor blade dovetail, the inclined surface being a curved surface, is cut in a concave shape formed with a spherical surface.
  • the drawing at the bottom of FIG. 17 partially illustrates the rotor blade dovetail in this embodiment when viewed from above.
  • FIG. 18 partially illustrates a rotor blade dovetail that secures a rotor blade included in an axial flow compressor according to a sixteenth embodiment of the present invention; the downstream side of the inclined surface of the rotor blade dovetail, the inclined surface being a curved surface, is cut in a convex shape formed with a spherical surface.
  • the drawing at the bottom of FIG. 18 partially illustrates the rotor blade dovetail in this embodiment when viewed from above.
  • FIG. 19 partially illustrates a rotor blade dovetail that secures a rotor blade included in an axial flow compressor according to a seventeenth embodiment of the present invention; the downstream side of the inclined surface of the rotor blade dovetail, the inclined surface being a curved surface, is cut in a concave shape formed with a curved surface.
  • the drawing at the bottom of FIG. 19 partially illustrates the rotor blade dovetail in this embodiment when viewed from above.
  • FIG. 20 partially illustrates a rotor blade dovetail that secures a rotor blade included in an axial flow compressor according to an eighteenth embodiment of the present invention; the downstream side of the inclined surface of the rotor blade dovetail, the inclined surface being a curved surface, is cut in a convex shape formed with a curved surface.
  • the drawing at the bottom of FIG. 20 partially illustrates the rotor blade dovetail in this embodiment when viewed from above.
  • FIG. 21 partially illustrates a rotor blade dovetail that secures a rotor blade included in an axial flow compressor according to a nineteenth embodiment of the present invention; the downstream side of the inclined surface of the rotor blade dovetail, the inclined surface being a curved surface, is cut in a concave shape consisting of a plurality of flat surfaces.
  • the drawing at the bottom of FIG. 21 partially illustrates the rotor blade dovetail in this embodiment when viewed from above.
  • FIG. 22 partially illustrates a rotor blade dovetail that secures a rotor blade included in an axial flow compressor according to a twentieth embodiment of the present invention; the downstream side of the inclined surface of the rotor blade dovetail, the inclined surface being a curved surface, is cut in a convex shape consisting of a plurality of flat surfaces.
  • the drawing at the bottom of FIG. 22 partially illustrates the rotor blade dovetail in this embodiment when viewed from above.
  • FIG. 23 partially illustrates a rotor blade dovetail that secures a rotor blade included in an axial flow compressor according to a twenty-first embodiment of the present invention; the downstream side of the inclined surface of the rotor blade dovetail, the inclined surface being a flat surface, is cut in a planar shape.
  • the drawing at the bottom of FIG. 23 partially illustrates the rotor blade dovetail in this embodiment when viewed from above.
  • FIG. 24 partially illustrates a rotor blade dovetail that secures a rotor blade included in an axial flow compressor according to a twenty-second embodiment of the present invention; the downstream side of the inclined surface of the rotor blade dovetail, the inclined surface being a flat surface, is cut in a concave shape formed with a curved surface.
  • the drawing at the bottom of FIG. 24 partially illustrates the rotor blade dovetail in this embodiment when viewed from above.
  • FIG. 25 partially illustrates a rotor blade dovetail that secures a rotor blade included in an axial flow compressor according to a twenty-third embodiment of the present invention; the downstream side of the inclined surface of the rotor blade dovetail, the inclined surface being a flat surface, is cut in a convex shape formed with a curved surface.
  • the drawing at the bottom of FIG. 25 partially illustrates the rotor blade dovetail in this embodiment when viewed from above.
  • FIG. 26 partially illustrates a rotor blade dovetail that secures a rotor blade included in an axial flow compressor according to a twenty-fourth embodiment of the present invention; the downstream side of the inclined surface of the rotor blade dovetail, the inclined surface being a flat surface, is cut in a concave shape consisting of a plurality of flat surfaces.
  • the drawing at the bottom of FIG. 26 partially illustrates the rotor blade dovetail in this embodiment when viewed from above.
  • FIG. 27 partially illustrates a rotor blade dovetail that secures a rotor blade included in an axial flow compressor according to a twenty-fifth embodiment of the present invention; the downstream side of the inclined surface of the rotor blade dovetail, the inclined surface being a flat surface, is cut in a convex shape consisting of a plurality of flat surfaces.
  • the drawing at the bottom of FIG. 27 partially illustrates the rotor blade dovetail in this embodiment when viewed from above.
  • FIG. 28 partially illustrates a rotor blade dovetail that secures a rotor blade included in an axial flow compressor according to a twenty-sixth embodiment of the present invention; both the upstream side and the downstream side of the inclined surface of the rotor blade dovetail, the inclined surface being a curved surface, are cut in a concave shape formed with a spherical surface.
  • the drawing at the bottom of FIG. 28 partially illustrates the rotor blade dovetail in this embodiment when viewed from above.
  • FIG. 29 partially illustrates a rotor blade dovetail that secures a rotor blade included in an axial flow compressor according to a twenty-seventh embodiment of the present invention; both the upstream side and the downstream side of the inclined surface of the rotor blade dovetail, the inclined surface being a curved surface, are cut in a convex shape formed with a spherical surface.
  • the drawing at the bottom of FIG. 29 partially illustrates the rotor blade dovetail in this embodiment when viewed from above.
  • FIG. 30 partially illustrates a rotor blade dovetail that secures a rotor blade included in an axial flow compressor according to a twenty-eighth embodiment of the present invention; both the upstream side and the downstream side of the inclined surface of the rotor blade dovetail, the inclined surface being a curved surface, are cut in a concave shape formed with a spherical surface.
  • the drawing at the bottom of FIG. 30 partially illustrates the rotor blade dovetail in this embodiment when viewed from above.
  • FIG. 31 partially illustrates a rotor blade dovetail that secures a rotor blade included in an axial flow compressor according to a twenty-ninth embodiment of the present invention; both the upstream side and the downstream side of the inclined surface of the rotor blade dovetail, the inclined surface being a curved surface, are cut in a convex shape formed with a curved surface.
  • the drawing at the bottom of FIG. 31 partially illustrates the rotor blade dovetail in this embodiment when viewed from above.
  • FIG. 32 partially illustrates a rotor blade dovetail that secures a rotor blade included in an axial flow compressor according to a thirtieth embodiment of the present invention; both the upstream side and the downstream side of the inclined surface of the rotor blade dovetail, the inclined surface being a curved surface, are cut in a concave shape consisting of a plurality of flat surfaces.
  • the drawing at the bottom of FIG. 32 partially illustrates the rotor blade dovetail in this embodiment when viewed from above.
  • FIG. 33 partially illustrates a rotor blade dovetail that secures a rotor blade included in an axial flow compressor according to a thirty-first embodiment of the present invention; both the upstream side and the downstream side of the inclined surface of the rotor blade dovetail, the inclined surface being a curved surface, are cut in a convex shape consisting of a plurality of flat surfaces.
  • the drawing at the bottom of FIG. 33 partially illustrates the rotor blade dovetail in this embodiment when viewed from above.
  • FIG. 34 partially illustrates a rotor blade dovetail that secures a rotor blade included in an axial flow compressor according to a thirty-second embodiment of the present invention; both the upstream side and the downstream side of the inclined surface of the rotor blade dovetail, the inclined surface being a flat surface, are cut in a planner shape.
  • the drawing at the bottom of FIG. 34 partially illustrates the rotor blade dovetail in this embodiment when viewed from above.
  • FIG. 35 partially illustrates a rotor blade dovetail that secures a rotor blade included in an axial flow compressor according to a thirty-third embodiment of the present invention; both the upstream side and the downstream side of the inclined surface of the rotor blade dovetail, the inclined surface being a flat surface, are cut in a concave shape formed with a curved surface.
  • the drawing at the bottom of FIG. 35 partially illustrates the rotor blade dovetail in this embodiment when viewed from above.
  • FIG. 36 partially illustrates a rotor blade dovetail that secures a rotor blade included in an axial flow compressor according to a thirty-fourth embodiment of the present invention; both the upstream side and the downstream side of the inclined surface of the rotor blade dovetail, the inclined surface being a flat surface, are cut in a convex shape formed with a curved surface.
  • the drawing at the bottom of FIG. 36 partially illustrates the rotor blade dovetail in this embodiment when viewed from above.
  • FIG. 37 partially illustrates a rotor blade dovetail that secures a rotor blade included in an axial flow compressor according to a thirty-fifth embodiment of the present invention; both the upstream side and the downstream side of the inclined surface of the rotor blade dovetail, the inclined surface being a flat surface, are cut in a concave shape consisting of a plurality of flat surfaces.
  • the drawing at the bottom of FIG. 37 partially illustrates the rotor blade dovetail in this embodiment when viewed from above.
  • FIG. 38 partially illustrates a rotor blade dovetail that secures a rotor blade included in an axial flow compressor according to a thirty-sixth embodiment of the present invention; both the upstream side and the downstream side of the inclined surface of the rotor blade dovetail, the inclined surface being a flat surface, are cut in a convex shape consisting of a plurality of flat surfaces.
  • the drawing at the bottom of FIG. 38 partially illustrates the rotor blade dovetail in this embodiment when viewed from above.
  • FIGS. 1 to 3 A first embodiment of the axial flow compressor according to the present invention will be described with reference to FIGS. 1 to 3 .
  • FIG. 1 partially illustrates a rotor blade dovetail 5 that secures a rotor blade 4 included in the axial flow compressor according to the first embodiment of the present invention; on the upstream side of the inclined surface 7 of the rotor blade dovetail 5 , the inclined surface 7 being a curved surface, a flat surface 6 , which is a cut flat surface, is formed.
  • FIG. 1 partially illustrates the rotor blade dovetail 5 in this embodiment when viewed from above.
  • the rotor blade dovetail 5 that secures the rotor blade 4 included in the axial flow compressor, illustrated in FIG. 1 , according to the first embodiment has the flat surface 6 , which is a cut surface formed by cutting part of the rotor blade dovetail 5 on the upstream side in the flow direction of a working fluid toward a maximum width part 7 c of the inclined surface 7 , on an end surface 5 a of the rotor blade dovetail 5 on the upstream side of the inclined surface 7 , which is a curved surface.
  • the rotor blade dovetail 5 is provided at the bottom of each of a plurality of rotor blades 4 , which are part of the axial flow compressor 1 according to this embodiment. Since the rotor blade 4 is placed at a certain angle with respect to the direction of the rotational axis as illustrated in FIG. 2 , the rotor blade dovetail 5 is also placed at a certain angle with respect to the direction of the rotational axis.
  • a plurality of wheel dovetails 14 are placed on the outer surface of a compressor wheel 8 , which is a rotating body of the axial flow compressor 1 , at a certain angle with respect to the direction of the rotational axis of the rotating body.
  • One rotor blade dovetail 5 is fitted into the inside of each wheel dovetail 14 , forming the rotating body of the axial flow compressor 1 .
  • the axial flow compressor 1 As illustrated in FIG. 3 , the axial flow compressor 1 according to the first embodiment comprising a rotor blade 4 and a stator blade 18 to intake air from an atmosphere and compress the air as a working fluid, a wheel 8 that secures the rotor blade 4 , and a casing that secures the stator blade 18 .
  • the rotor blade dovetail 5 that secures the rotor blade 4 included in the axial flow compressor according to the first embodiment has the flat surface 6 , which is a cut surface formed by cutting part of the rotor blade dovetail 5 on the upstream side in the flow direction of a working fluid toward the maximum width part 7 c of the inclined surface 7 , on the end surface 5 a of the rotor blade dovetail 5 on the upstream side of the inclined surface 7 , which is a curved surface.
  • this embodiment uses a structure in which the flat surface 6 , which is a cut surface, is formed on the end surface 5 a of the rotor blade dovetail 5 on the upstream side of the inclined surface 7 , which is a curved surface, in the flow direction of a working fluid, an uneven contact with the wheel dovetail 14 can be reduced and a load exerted from the rotor blade 4 can thereby be evened; the load would otherwise become asymmetric between the forward direction and reverse direction of the rotational direction of the rotor blade 4 . As a result, high stress exerted on the rotor blade 4 can be reduced.
  • an axial flow compressor having rotor blade dovetails that reduce an uneven contact with each wheel dovetail so as to level a load, exerted from the relevant rotor blade, that would otherwise become asymmetric between the forward direction and reverse direction of the rotational direction of the rotor blade and to thereby reduce high stress exerted on the rotor blade, and a gas turbine, can be realized.
  • the rotor blade dovetail 5 in the axial flow compressor 1 according to a second embodiment of the present invention will be described with reference to FIG. 4 .
  • the basic structure of the axial flow compressor 1 in the second embodiment illustrated in FIG. 4 is the same as in the first embodiment of the axial flow compressor 1 according to the present invention illustrated in FIGS. 1 to 3 , so descriptions of structures common to these two embodiments will be omitted and only differences between them will be described.
  • FIG. 4 partially illustrates the rotor blade dovetail 5 that secures the rotor blade 4 included in the axial flow compressor 1 according to the second embodiment of the present invention; on an end surface 5 b of the rotor blade dovetail 5 on the downstream side of the inclined surface 7 , which is a curved surface, a flat surface 6 b is formed, which is a cut surface formed by cutting part of the rotor blade dovetail 5 on the downstream side in the flow direction of a working fluid toward the maximum width part 7 c of the inclined surface 7 .
  • This embodiment described above uses a structure in which the flat surface 6 b , which is a cut surface, is formed on the end surface 5 b of the rotor blade dovetail 5 on the downstream side of the inclined surface 7 , which is a curved surface, so a load exerted from the rotor blade 4 can be evened; the load would otherwise become asymmetric between the forward direction and reverse direction of the rotational direction of the rotor blade 4 . As a result, high stress exerted on the rotor blade 4 can be reduced.
  • an axial flow compressor having rotor blade dovetails that reduce an uneven contact with each wheel dovetail so as to level a load, exerted from the relevant rotor blade, that would otherwise become asymmetric between the forward direction and reverse direction of the rotational direction of the rotor blade and to thereby reduce high stress exerted on the rotor blade, and a gas turbine, can be realized.
  • the rotor blade dovetail 5 in the axial flow compressor 1 according to a third embodiment of the present invention will be described with reference to FIG. 5 .
  • the rotor blade dovetail 5 of the axial flow compressor 1 in the third embodiment illustrated in FIG. 5 has the same basic structure as the rotor blade dovetail 5 in the first embodiment of the axial flow compressor 1 according to the present invention illustrated in FIGS. 1 to 3 , so descriptions of structures common to these two embodiments will be omitted and only differences between them will be described.
  • the rotor blade dovetails in the axial flow compressors in a third embodiment and later in the present invention also have the same basic structure as the rotor blade dovetail 5 in the first embodiment of the axial flow compressor 1 according to the present invention illustrated in FIGS. 1 to 3 , so descriptions of structures common to the relevant embodiment and the first embodiment will be omitted and only differences between them will be described.
  • FIG. 5 partially illustrates the rotor blade dovetail 5 that secures the rotor blade 4 included in the axial flow compressor according to the third embodiment of the present invention
  • the flat surface 6 is formed, which is a cut surface formed by cutting part of the rotor blade dovetail 5 on the upstream side in the flow direction of a working fluid toward the maximum width part 7 c of the inclined surface 7
  • the flat surface 6 b is formed, which is a cut surface formed by cutting part of the rotor blade dovetail 5 toward the maximum width part 7 c of the inclined surface 7 .
  • This embodiment described above uses a structure in which the flat surface 6 , which is a cut surface, is formed on the end surface 5 a of the rotor blade dovetail 5 on the upstream side of the inclined surface 7 , which is a curved surface, and the flat surface 6 b , which is a cut surface, is also formed on the end surface 5 b of the rotor blade dovetail 5 on the downstream side of the inclined surface 7 , so an uneven contact with the wheel dovetail 14 can be greatly reduced on both the upstream side and downstream side of the rotor blade dovetail 5 .
  • an axial flow compressor having rotor blade dovetails that reduce an uneven contact with each wheel dovetail so as to level a load, exerted from the relevant rotor blade, that would otherwise become asymmetric between the forward direction and reverse direction of the rotational direction of the rotor blade and to thereby reduce high stress exerted on the rotor blade, and a gas turbine, can be realized.
  • the rotor blade dovetail 5 in the axial flow compressor according to a fourth embodiment of the present invention will be described with reference to FIG. 6 .
  • FIG. 6 partially illustrates the rotor blade dovetail 5 that secures the rotor blade 4 included in the axial flow compressor according to the fourth embodiment of the present invention; on the end surface 5 a of the rotor blade dovetail 5 on the upstream side of the inclined surface 7 , which is a curved surface, a spherical concave surface 15 is formed, which is a cut surface.
  • This embodiment described above uses a structure in which the spherical concave surface 15 , which is a cut surface formed by cutting part of the rotor blade dovetail 5 on the upstream side in the flow direction of a working fluid toward the maximum width part 7 c of the inclined surface 7 , is formed on the end surface 5 a of the rotor blade dovetail 5 on the upstream side of the inclined surface 7 , which is a curved surface. Therefore, a load exerted from the rotor blade 4 can be evened; the load would otherwise become asymmetric between the forward direction and reverse direction of the rotational direction of the rotor blade 4 . As a result, high stress exerted on the rotor blade 4 can be reduced.
  • the cut surface is the spherical concave surface 15 instead of the flat surface 6 in the first embodiment. Therefore, the rotor blade dovetail 5 in the axial flow compressor in this embodiment is lighter than the rotor blade dovetail 5 in the axial flow compressor in the first embodiment by the amount of formation of the spherical concave surface 15 , so an advantage of reducing stress exerted on the rotor blade dovetail 5 can be obtained.
  • an axial flow compressor having rotor blade dovetails that reduce an uneven contact with each wheel dovetail so as to level a load, exerted from the relevant rotor blade, that would otherwise become asymmetric between the forward direction and reverse direction of the rotational direction of the rotor blade and to thereby reduce high stress exerted on the rotor blade, and a gas turbine, can be realized.
  • the rotor blade dovetail 5 in the axial flow compressor according to a fifth embodiment of the present invention will be described with reference to FIG. 7 .
  • FIG. 7 partially illustrates the rotor blade dovetail 5 that secures the rotor blade 4 included in the axial flow compressor according to the fifth embodiment of the present invention; on the end surface 5 a of the rotor blade dovetail 5 on the upstream side of the inclined surface 7 , which is a curved surface, a spherical convex surface 16 is formed, which is a cut surface.
  • This embodiment described above uses a structure in which the spherical convex surface 16 , which is a cut surface formed by cutting part of the rotor blade dovetail 5 on the upstream side in the flow direction of a working fluid toward the maximum width part 7 c of the inclined surface 7 , is formed on the end surface 5 a of the rotor blade dovetail 5 on the upstream side of the inclined surface 7 , which is a curved surface. Therefore, a load exerted from the rotor blade 4 can be evened; the load would otherwise become asymmetric between the forward direction and reverse direction of the rotational direction of the rotor blade 4 . As a result, high stress exerted on the rotor blade 4 can be reduced.
  • the cut surface is the spherical convex surface 16 . This is preferable for the wheel dovetail 14 in terms of strength.
  • an axial flow compressor having rotor blade dovetails that reduce an uneven contact with each wheel dovetail so as to level a load, exerted from the relevant rotor blade, that would otherwise become asymmetric between the forward direction and reverse direction of the rotational direction of the rotor blade and to thereby reduce high stress exerted on the rotor blade, and a gas turbine, can be realized.
  • the rotor blade dovetail 5 in the axial flow compressor 1 according to a sixth embodiment of the present invention will be described with reference to FIG. 8 .
  • FIG. 8 partially illustrates the rotor blade dovetail 5 that secures the rotor blade 4 included in the axial flow compressor according to the sixth embodiment of the present invention; on the end surface 5 a of the rotor blade dovetail 5 on the upstream side of the inclined surface 7 , which is a curved surface, a curved concave surface 9 is formed, which is a cut surface.
  • This embodiment described above uses a structure in which the curved concave surface 9 , which is a cut surface formed by cutting part of the rotor blade dovetail 5 on the upstream side in the flow direction of a working fluid toward the maximum width part 7 c of the inclined surface 7 , is formed on the end surface 5 a of the rotor blade dovetail 5 on the upstream side of the inclined surface 7 , which is a curved surface. Therefore, a load exerted from the rotor blade 4 can be evened; the load would otherwise become asymmetric between the forward direction and reverse direction of the rotational direction of the rotor blade 4 . As a result, high stress exerted on the rotor blade 4 can be reduced.
  • the cut surface is the curved concave surface 9 , so the weight of the rotor blade dovetail 5 is reduced by the amount of formation of the curved concave surface 9 .
  • This is advantageous in that stress exerted on the rotor blade dovetail 5 can be reduced.
  • Another advantage obtained by forming a cut surface of the rotor blade dovetail 5 in the curved concave surface 9 is that machining is easier than when forming a cut surface of the rotor blade dovetail 5 in the spherical concave surface 15 .
  • an axial flow compressor having rotor blade dovetails that reduce an uneven contact with each wheel dovetail so as to level a load, exerted from the relevant rotor blade, that would otherwise become asymmetric between the forward direction and reverse direction of the rotational direction of the rotor blade and to thereby reduce high stress exerted on the rotor blade, and a gas turbine, can be realized.
  • the rotor blade dovetail 5 in the axial flow compressor according to a seventh embodiment of the present invention will be described with reference to FIG. 9 .
  • FIG. 9 partially illustrates the rotor blade dovetail 5 that secures the rotor blade 4 included in the axial flow compressor according to the seventh embodiment of the present invention; on the end surface 5 a of the rotor blade dovetail 5 on the upstream side of the inclined surface 7 , which is a curved surface, a curved convex surface 10 is formed, which is a cut surface.
  • This embodiment described above uses a structure in which the curved convex surface 10 , which is a cut surface, is formed on the end surface 5 a of the rotor blade dovetail 5 on the upstream side of the inclined surface 7 , which is a curved surface. Therefore, a load exerted from the rotor blade 4 can be evened; the load would otherwise become asymmetric between the forward direction and reverse direction of the rotational direction of the rotor blade 4 . As a result, high stress exerted on the rotor blade 4 can be reduced.
  • the cut surface is the curved convex surface 10 , so the weight of the rotor blade dovetail 5 is reduced by the amount of formation of the curved convex surface 10 .
  • This is advantageous in that stress exerted on the rotor blade dovetail 5 can be reduced.
  • Another advantage obtained by forming a cut surface of the rotor blade dovetail 5 in the curved convex surface 10 is that machining is easier than when forming a cut surface of the rotor blade dovetail 5 in the spherical convex surface 16 .
  • an axial flow compressor having rotor blade dovetails that reduce an uneven contact with each wheel dovetail so as to level a load, exerted from the relevant rotor blade, that would otherwise become asymmetric between the forward direction and reverse direction of the rotational direction of the rotor blade and to thereby reduce high stress exerted on the rotor blade, and a gas turbine, can be realized.
  • the rotor blade dovetail 5 in the axial flow compressor according to an eighth embodiment of the present invention will be described with reference to FIG. 10 .
  • FIG. 10 partially illustrates the rotor blade dovetail 5 that secures the rotor blade 4 included in the axial flow compressor according to the eighth embodiment of the present invention; on the end surface 5 a of the rotor blade dovetail 5 on the upstream side of the inclined surface 7 , which is a curved surface, a concave surface 12 consisting of a plurality of flat surfaces, each being a cut surface, is formed.
  • This embodiment described above uses a structure in which the concave surface 12 consisting of a plurality of flat surfaces, each of which is a cut surface formed by cutting part of the rotor blade dovetail 5 on the upstream side in the flow direction of a working fluid toward the maximum width part 7 c of the inclined surface 7 , is formed on the end surface 5 a of the rotor blade dovetail 5 on the upstream side of the inclined surface 7 , which is a curved surface. Therefore, a load exerted from the rotor blade 4 can be evened; the load would otherwise become asymmetric between the forward direction and reverse direction of the rotational direction of the rotor blade 4 . As a result, high stress exerted on the rotor blade 4 can be reduced.
  • the cut surface is the concave surface 12 consisting of a plurality of flat surfaces, so the weight of the rotor blade dovetail 5 is reduced by the amount of formation of the concave surface 12 .
  • This is advantageous in that stress exerted on the rotor blade dovetail 5 can be reduced.
  • Another advantage obtained by forming a cut surface of the rotor blade dovetail 5 in the concave surface 12 consisting of a plurality of flat surfaces is that machining is easier than when forming a cut surface of the rotor blade dovetail 5 in the spherical concave surface 15 or curved concave surface 9 .
  • an axial flow compressor having rotor blade dovetails that reduce an uneven contact with each wheel dovetail so as to level a load, exerted from the relevant rotor blade, that would otherwise become asymmetric between the forward direction and reverse direction of the rotational direction of the rotor blade and to thereby reduce high stress exerted on the rotor blade, and a gas turbine, can be realized.
  • the rotor blade dovetail 5 in the axial flow compressor according to a ninth embodiment of the present invention will be described with reference to FIG. 11 .
  • FIG. 11 partially illustrates the rotor blade dovetail 5 that secures the rotor blade 4 included in the axial flow compressor according to the ninth embodiment of the present invention; on the end surface 5 a of the rotor blade dovetail 5 on the upstream side of the inclined surface 7 , which is a curved surface, a convex surface 13 consisting of a plurality of flat surfaces, each being a cut surface, is formed.
  • This embodiment described above uses a structure in which the convex surface 13 consisting of a plurality of flat surfaces, each of which is a cut surface formed by cutting part of the rotor blade dovetail 5 on the upstream side in the flow direction of a working fluid toward the maximum width part 7 c of the inclined surface 7 , is formed on the end surface 5 a of the rotor blade dovetail 5 on the upstream side of the inclined surface 7 , which is a curved surface. Therefore, a load exerted from the rotor blade 4 can be evened; the load would otherwise become asymmetric between the forward direction and reverse direction of the rotational direction of the rotor blade 4 . As a result, high stress exerted on the rotor blade 4 can be reduced.
  • the cut surface is the convex surface 13 consisting of a plurality of flat surfaces, so the weight of the rotor blade dovetail 5 is reduced by the amount of formation of the convex surface 13 .
  • This is advantageous in that stress exerted on the rotor blade dovetail 5 can be reduced.
  • Another advantage obtained by forming a cut surface of the rotor blade dovetail 5 in the convex surface 13 consisting of a plurality of flat surfaces is that machining is easier than when forming a cut surface of the rotor blade dovetail 5 in the spherical convex surface 16 or curved convex surface 10 .
  • an axial flow compressor having rotor blade dovetails that reduce an uneven contact with each wheel dovetail so as to level a load, exerted from the relevant rotor blade, that would otherwise become asymmetric between the forward direction and reverse direction of the rotational direction of the rotor blade and to thereby reduce high stress exerted on the rotor blade, and a gas turbine, can be realized.
  • the rotor blade dovetail 5 in the axial flow compressor according to a tenth embodiment of the present invention will be described with reference to FIG. 12 .
  • FIG. 12 partially illustrates the rotor blade dovetail 5 that secures the rotor blade 4 included in the axial flow compressor according to the tenth embodiment of the present invention; on the end surface 5 a of the rotor blade dovetail 5 on the upstream side of an inclined surface 11 , which is a flat surface, the flat surface 6 , which is a cut surface, is formed.
  • This embodiment described above uses a structure in which the flat surface 6 , which is a cut surface formed by cutting part of the rotor blade dovetail 5 on the upstream side in the flow direction of a working fluid toward the maximum width part 11 c of the inclined surface 11 , is formed on the end surface 5 a of the rotor blade dovetail 5 on the upstream side of the inclined surface 11 , which is a flat surface. Therefore, a load exerted from the rotor blade 4 can be evened; the load would otherwise become asymmetric between the forward direction and reverse direction of the rotational direction of the rotor blade 4 . As a result, high stress exerted on the rotor blade 4 can be reduced.
  • an axial flow compressor having rotor blade dovetails that reduce an uneven contact with each wheel dovetail so as to level a load, exerted from the relevant rotor blade, that would otherwise become asymmetric between the forward direction and reverse direction of the rotational direction of the rotor blade and to thereby reduce high stress exerted on the rotor blade, and a gas turbine, can be realized.
  • the rotor blade dovetail 5 in the axial flow compressor according to an eleventh embodiment of the present invention will be described with reference to FIG. 13 .
  • FIG. 13 partially illustrates the rotor blade dovetail 5 that secures the rotor blade 4 included in the axial flow compressor according to the eleventh embodiment of the present invention; on the end surface 5 a of the rotor blade dovetail 5 on the upstream side of the inclined surface 11 , which is a cut surface, the curved concave surface 9 is formed, which is a cut surface.
  • This embodiment described above uses a structure in which the curved concave surface 9 , which is a cut surface, is formed on the end surface 5 a of the rotor blade dovetail 5 on the upstream side of the inclined surface 11 , which is a flat surface. Therefore, a load exerted from the rotor blade 4 can be evened; the load would otherwise become asymmetric between the forward direction and reverse direction of the rotational direction of the rotor blade 4 . As a result, high stress exerted on the rotor blade 4 can be reduced.
  • This embodiment described above uses a structure in which the curved concave surface 9 , which is a cut surface formed by cutting part of the rotor blade dovetail 5 on the upstream side in the flow direction of a working fluid toward the maximum width part 11 c of the inclined surface 11 , is formed on the end surface 5 a of the rotor blade dovetail 5 on the upstream side of the inclined surface 11 . Therefore, a load exerted from the rotor blade 4 can be evened; the load would otherwise become asymmetric between the forward direction and reverse direction of the rotational direction of the rotor blade 4 . As a result, high stress exerted on the rotor blade 4 can be reduced.
  • the cut surface is the curved concave surface 9 , so the weight of the rotor blade dovetail 5 is reduced by the amount of formation of the curved concave surface 9 .
  • This is advantageous in that stress exerted on the rotor blade dovetail 5 can be reduced.
  • Another advantage obtained by forming a cut surface of the rotor blade dovetail 5 in the curved concave surface 9 is that machining is easier than when forming a cut surface of the rotor blade dovetail 5 in the spherical concave surface 15 .
  • the inclined surface 11 of the rotor blade dovetail 5 is a flat surface, so the weight of the rotor blade dovetail 5 is reduced by the amount of formation of the inclined surface 11 as a flat surface. This is advantageous in that stress exerted on the rotor blade dovetail 5 can be reduced.
  • an axial flow compressor having rotor blade dovetails that reduce an uneven contact with each wheel dovetail so as to level a load, exerted from the relevant rotor blade, that would otherwise become asymmetric between the forward direction and reverse direction of the rotational direction of the rotor blade and to thereby reduce high stress exerted on the rotor blade, and a gas turbine, can be realized.
  • the rotor blade dovetail 5 in the axial flow compressor according to a twelfth embodiment of the present invention will be described with reference to FIG. 14 .
  • FIG. 14 partially illustrates the rotor blade dovetail 5 that secures the rotor blade 4 included in the axial flow compressor according to the twelfth embodiment of the present invention; on the end surface 5 a of the rotor blade dovetail 5 on the upstream side of the inclined surface 11 , which is a cut surface, the curved convex surface 10 is formed, which is a cut surface.
  • This embodiment described above uses a structure in which the curved convex surface 10 , which is a cut surface formed by cutting part of the rotor blade dovetail 5 on the upstream side in the flow direction of a working fluid toward the maximum width part lic of the inclined surface 11 , is formed on the end surface 5 a of the rotor blade dovetail 5 on the upstream side of the inclined surface 11 , which is a curved surface. Therefore, a load exerted from the rotor blade 4 can be evened; the load would otherwise become asymmetric between the forward direction and reverse direction of the rotational direction of the rotor blade 4 . As a result, high stress exerted on the rotor blade 4 can be reduced.
  • the cut surface is the curved convex surface 10 , so the weight of the rotor blade dovetail 5 is reduced by the amount of formation of the curved convex surface 10 .
  • This is advantageous in that stress exerted on the rotor blade dovetail 5 can be reduced.
  • Another advantage obtained by forming a cut surface of the rotor blade dovetail 5 in the curved convex surface 10 is that machining is easier than when forming a cut surface of the rotor blade dovetail 5 in the spherical convex surface 16 .
  • the inclined surface 11 of the rotor blade dovetail 5 is a flat surface, so the weight of the rotor blade dovetail 5 is reduced by the amount of formation of the inclined surface 11 as a flat surface. This is advantageous in that stress exerted on the rotor blade dovetail 5 can be reduced.
  • an axial flow compressor having rotor blade dovetails that reduce an uneven contact with each wheel dovetail so as to level a load, exerted from the relevant rotor blade, that would otherwise become asymmetric between the forward direction and reverse direction of the rotational direction of the rotor blade and to thereby reduce high stress exerted on the rotor blade, and a gas turbine, can be realized.
  • the rotor blade dovetail 5 in the axial flow compressor according to a thirteenth embodiment of the present invention will be described with reference to FIG. 15 .
  • FIG. 15 partially illustrates the rotor blade dovetail 5 that secures the rotor blade 4 included in the axial flow compressor according to the thirteenth embodiment of the present invention; on the end surface 5 a of the rotor blade dovetail 5 on the upstream side of the inclined surface 11 , which is a flat surface, the concave surface 12 consisting of a plurality of flat surfaces, each being a cut surface, is formed.
  • This embodiment described above uses a structure in which the concave surface 12 consisting of a plurality of flat surfaces, each of which is a cut surface formed by cutting part of the rotor blade dovetail 5 on the upstream side in the flow direction of a working fluid toward the maximum width part 11 c of the inclined surface 11 , is formed on the end surface 5 a of the rotor blade dovetail 5 on the upstream side of the inclined surface 11 , which is a flat surface. Therefore, a load exerted from the rotor blade 4 can be evened; the load would otherwise become asymmetric between the forward direction and reverse direction of the rotational direction of the rotor blade 4 . As a result, high stress exerted on the rotor blade 4 can be reduced.
  • the cut surface is the concave surface 12 consisting of a plurality of flat surfaces, so the weight of the rotor blade dovetail 5 is reduced by the amount of formation of the concave surface 12 .
  • This is advantageous in that stress exerted on the rotor blade dovetail 5 can be reduced.
  • Another advantage obtained by forming a cut surface of the rotor blade dovetail 5 in the concave surface 12 consisting of a plurality of flat surfaces is that machining is easier than when forming a cut surface of the rotor blade dovetail 5 in the spherical concave surface 15 .
  • the inclined surface 11 of the rotor blade dovetail 5 is a flat surface, so the weight of the rotor blade dovetail 5 is reduced by the amount of formation of the inclined surface 11 as a flat surface. This is advantageous in that stress exerted on the rotor blade dovetail 5 can be reduced.
  • an axial flow compressor having rotor blade dovetails that reduce an uneven contact with each wheel dovetail so as to level a load, exerted from the relevant rotor blade, that would otherwise become asymmetric between the forward direction and reverse direction of the rotational direction of the rotor blade and to thereby reduce high stress exerted on the rotor blade, and a gas turbine, can be realized.
  • the rotor blade dovetail 5 in the axial flow compressor according to a fourteenth embodiment of the present invention will be described with reference to FIG. 16 .
  • FIG. 16 partially illustrates the rotor blade dovetail 5 that secures the rotor blade 4 included in the axial flow compressor according to the fourteenth embodiment of the present invention; on the end surface 5 a of the rotor blade dovetail 5 on the upstream side of the inclined surface 11 , which is a flat surface, the concave surface 13 consisting of a plurality of flat surfaces, each being a cut surface, is formed.
  • This embodiment described above uses a structure in which the convex surface 13 consisting of a plurality of flat surfaces, each of which is a cut surface formed by cutting part of the rotor blade dovetail 5 on the upstream side in the flow direction of a working fluid toward the maximum width part 11 c of the inclined surface 11 , is formed on the end surface 5 a of the rotor blade dovetail 5 on the upstream side of the inclined surface 11 , which is a flat surface. Therefore, a load exerted from the rotor blade 4 can be evened; the load would otherwise become asymmetric between the forward direction and reverse direction of the rotational direction of the rotor blade 4 . As a result, high stress exerted on the rotor blade 4 can be reduced.
  • the cut surface is the convex surface 13 consisting of a plurality of flat surfaces, so the weight of the rotor blade dovetail 5 is reduced by the amount of formation of the convex surface 13 .
  • This is advantageous in that stress exerted on the rotor blade dovetail 5 can be reduced.
  • Another advantage obtained by forming a cut surface of the rotor blade dovetail 5 in the convex surface 13 consisting of a plurality of flat surfaces is that machining is easier than when forming a cut surface of the rotor blade dovetail 5 in the spherical convex surface 16 .
  • the inclined surface 11 of the rotor blade dovetail 5 is a flat surface, so the weight of the rotor blade dovetail 5 is reduced by the amount of formation of the inclined surface 11 as a flat surface. This is advantageous in that stress exerted on the rotor blade dovetail 5 can be reduced.
  • an axial flow compressor having rotor blade dovetails that reduce an uneven contact with each wheel dovetail so as to level a load, exerted from the relevant rotor blade, that would otherwise become asymmetric between the forward direction and reverse direction of the rotational direction of the rotor blade and to thereby reduce high stress exerted on the rotor blade, and a gas turbine, can be realized.
  • the rotor blade dovetail 5 in the axial flow compressor according to a fifteenth embodiment of the present invention will be described with reference to FIG. 17 .
  • FIG. 17 partially illustrates the rotor blade dovetail 5 that secures the rotor blade 4 included in the axial flow compressor according to the fifteenth embodiment of the present invention; on the end surface 5 b of the rotor blade dovetail 5 on the downstream side of the inclined surface 7 , which is a curved surface, a curved concave surface 15 b is formed, which is a cut surface.
  • This embodiment described above uses a structure in which the curved concave surface 15 b , which is a cut surface formed by cutting part of the rotor blade dovetail 5 on the downstream side in the flow direction of a working fluid toward the maximum width part 7 c of the inclined surface 7 , is formed on the end surface 5 b of the rotor blade dovetail 5 on the downstream side of the inclined surface 7 , which is a curved surface. Therefore, a load exerted from the rotor blade 4 can be evened; the load would otherwise become asymmetric between the forward direction and reverse direction of the rotational direction of the rotor blade 4 . As a result, high stress exerted on the rotor blade 4 can be reduced.
  • the cut surface is the curved concave surface 15 b , so the weight of the rotor blade dovetail 5 is reduced by the amount of formation of the spherical concave surface 15 b .
  • This is advantageous in that stress exerted on the rotor blade dovetail 5 can be reduced.
  • Another advantage obtained by forming a cut surface of the rotor blade dovetail 5 in the spherical concave surface 15 b is that machining is easier than when forming a cut surface of the rotor blade dovetail 5 in the spherical concave surface 15 .
  • an axial flow compressor having rotor blade dovetails that reduce an uneven contact with each wheel dovetail so as to level a load, exerted from the relevant rotor blade, that would otherwise become asymmetric between the forward direction and reverse direction of the rotational direction of the rotor blade and to thereby reduce high stress exerted on the rotor blade, and a gas turbine, can be realized.
  • the rotor blade dovetail 5 in the axial flow compressor according to a sixteenth embodiment of the present invention will be described with reference to FIG. 18 .
  • FIG. 18 partially illustrates the rotor blade dovetail 5 that secures the rotor blade 4 included in the axial flow compressor according to the sixteenth embodiment of the present invention; on the end surface 5 b of the rotor blade dovetail 5 on the downstream side of the inclined surface 7 , which is a curved surface, a curved convex surface 16 b is formed, which is a cut surface.
  • This embodiment described above uses a structure in which the curved convex surface 16 b , which is a cut surface formed by cutting part of the rotor blade dovetail 5 on the downstream side in the flow direction of a working fluid toward the maximum width part 7 c of the inclined surface 7 , is formed on the end surface 5 b of the rotor blade dovetail 5 on the downstream side of the inclined surface 7 , which is a curved surface. Therefore, a load exerted from the rotor blade 4 can be evened; the load would otherwise become asymmetric between the forward direction and reverse direction of the rotational direction of the rotor blade 4 . As a result, high stress exerted on the rotor blade 4 can be reduced.
  • the cut surface is the curved convex surface 16 b , so the weight of the rotor blade dovetail 5 is reduced by the amount of formation of the spherical convex surface 16 b .
  • This is advantageous in that stress exerted on the rotor blade dovetail 5 can be reduced.
  • Another advantage obtained by forming a cut surface of the rotor blade dovetail 5 in the spherical convex surface 16 b is that machining is easier than when forming a cut surface of the rotor blade dovetail 5 in the spherical convex surface 16 .
  • an axial flow compressor having rotor blade dovetails that reduce an uneven contact with each wheel dovetail so as to level a load, exerted from the relevant rotor blade, that would otherwise become asymmetric between the forward direction and reverse direction of the rotational direction of the rotor blade and to thereby reduce high stress exerted on the rotor blade, and a gas turbine, can be realized.
  • the rotor blade dovetail 5 in the axial flow compressor according to a seventeenth embodiment of the present invention will be described with reference to FIG. 19 .
  • FIG. 19 partially illustrates the rotor blade dovetail 5 that secures the rotor blade 4 included in the axial flow compressor according to the seventeenth embodiment of the present invention; on the end surface 5 b of the rotor blade dovetail 5 on the downstream side of the inclined surface 7 , which is a curved surface, a curved concave surface 9 b is formed, which is a cut surface.
  • This embodiment described above uses a structure in which the curved concave surface 9 b , which is a cut surface formed by cutting part of the rotor blade dovetail 5 on the downstream side in the flow direction of a working fluid toward the maximum width part 7 c of the inclined surface 7 , is formed on the end surface 5 b of the rotor blade dovetail 5 on the downstream side of the inclined surface 7 , which is a curved surface. Therefore, a load exerted from the rotor blade 4 can be evened; the load would otherwise become asymmetric between the forward direction and reverse direction of the rotational direction of the rotor blade 4 . As a result, high stress exerted on the rotor blade 4 can be reduced.
  • the cut surface is the curved concave surface 9 b , so the weight of the rotor blade dovetail 5 is reduced by the amount of formation of the curved concave surface 9 b .
  • This is advantageous in that stress exerted on the rotor blade dovetail 5 can be reduced.
  • Another advantage obtained by forming a cut surface of the rotor blade dovetail 5 in the curved concave surface 9 b is that machining is easier than when forming a cut surface of the rotor blade dovetail 5 in the spherical concave surface 15 .
  • an axial flow compressor having rotor blade dovetails that reduce an uneven contact with each wheel dovetail so as to level a load, exerted from the relevant rotor blade, that would otherwise become asymmetric between the forward direction and reverse direction of the rotational direction of the rotor blade and to thereby reduce high stress exerted on the rotor blade, and a gas turbine, can be realized.
  • the rotor blade dovetail 5 in the axial flow compressor according to an eighteenth embodiment of the present invention will be described with reference to FIG. 20 .
  • FIG. 20 partially illustrates the rotor blade dovetail 5 that secures the rotor blade 4 included in the axial flow compressor according to the eighteenth embodiment of the present invention; on the end surface 5 b of the rotor blade dovetail 5 on the downstream side of the inclined surface 7 , which is a curved surface, a curved convex surface 10 b is formed, which is a cut surface.
  • This embodiment described above uses a structure in which the curved convex surface 10 b , which is a cut surface formed by cutting part of the rotor blade dovetail 5 on the downstream side in the flow direction of a working fluid toward the maximum width part 7 c of the inclined surface 7 , is formed on the end surface 5 b of the rotor blade dovetail 5 on the downstream side of the inclined surface 7 , which is a curved surface. Therefore, a load exerted from the rotor blade 4 can be evened; the load would otherwise become asymmetric between the forward direction and reverse direction of the rotational direction of the rotor blade 4 . As a result, high stress exerted on the rotor blade 4 can be reduced.
  • the cut surface is the curved convex surface 10 b , so the weight of the rotor blade dovetail 5 is reduced by the amount of formation of the curved convex surface 10 b .
  • This is advantageous in that stress exerted on the rotor blade dovetail 5 can be reduced.
  • Another advantage obtained by forming a cut surface of the rotor blade dovetail 5 in the curved convex surface 10 b is that machining is easier than when forming a cut surface of the rotor blade dovetail 5 in the spherical convex surface 16 .
  • an axial flow compressor having rotor blade dovetails that reduce an uneven contact with each wheel dovetail so as to level a load, exerted from the relevant rotor blade, that would otherwise become asymmetric between the forward direction and reverse direction of the rotational direction of the rotor blade and to thereby reduce high stress exerted on the rotor blade, and a gas turbine, can be realized.
  • the rotor blade dovetail 5 in the axial flow compressor according to a nineteenth embodiment of the present invention will be described with reference to FIG. 21 .
  • FIG. 21 partially illustrates the rotor blade dovetail 5 that secures the rotor blade 4 included in the axial flow compressor according to the nineteenth embodiment of the present invention; on the end surface 5 b of the rotor blade dovetail 5 on the downstream side of the inclined surface 7 , which is a curved surface, a concave surface 12 b consisting of a plurality of flat surfaces, each being a cut surface, is formed.
  • This embodiment described above uses a structure in which the concave surface 12 b consisting of a plurality of flat surfaces, each of which is a cut surface formed by cutting part of the rotor blade dovetail 5 on the downstream side in the flow direction of a working fluid toward the maximum width part 7 c of the inclined surface 7 , is formed on the end surface 5 b of the rotor blade dovetail 5 on the downstream side of the inclined surface 7 , which is a curved surface. Therefore, a load exerted from the rotor blade 4 can be evened; the load would otherwise become asymmetric between the forward direction and reverse direction of the rotational direction of the rotor blade 4 . As a result, high stress exerted on the rotor blade 4 can be reduced.
  • the cut surface is the concave surface 12 b consisting of a plurality of flat surfaces, so the weight of the rotor blade dovetail 5 is reduced by the amount of formation of the concave surface 12 b .
  • This is advantageous in that stress exerted on the rotor blade dovetail 5 can be reduced.
  • Another advantage obtained by forming a cut surface of the rotor blade dovetail 5 in the concave surface 12 b consisting of a plurality of flat surfaces is that machining is easier than when forming a cut surface of the rotor blade dovetail 5 in the spherical concave surface 15 or curved concave surface 9 .
  • an axial flow compressor having rotor blade dovetails that reduce an uneven contact with each wheel dovetail so as to level a load, exerted from the relevant rotor blade, that would otherwise become asymmetric between the forward direction and reverse direction of the rotational direction of the rotor blade and to thereby reduce high stress exerted on the rotor blade, and a gas turbine, can be realized.
  • the rotor blade dovetail 5 in the axial flow compressor according to a twentieth embodiment of the present invention will be described with reference to FIG. 22 .
  • FIG. 22 partially illustrates the rotor blade dovetail 5 that secures the rotor blade 4 included in the axial flow compressor 1 according to the twentieth embodiment of the present invention; on the end surface 5 b of the rotor blade dovetail 5 on the downstream side of the inclined surface 7 , which is a curved surface, a convex surface 13 b consisting of a plurality of flat surfaces, each being a cut surface, is formed.
  • This embodiment described above uses a structure in which the convex surface 13 b consisting of a plurality of flat surfaces, each of which is a cut surface formed by cutting part of the rotor blade dovetail 5 on the downstream side in the flow direction of a working fluid toward the maximum width part 7 c of the inclined surface 7 , is formed on the end surface 5 b of the rotor blade dovetail 5 on the downstream side of the inclined surface 7 , which is a curved surface. Therefore, a load exerted from the rotor blade 4 can be evened; the load would otherwise become asymmetric between the forward direction and reverse direction of the rotational direction of the rotor blade 4 . As a result, high stress exerted on the rotor blade 4 can be reduced.
  • the cut surface is the convex surface 13 b consisting of a plurality of flat surfaces, so the weight of the rotor blade dovetail 5 is reduced by the amount of formation of the convex surface 13 b .
  • This is advantageous in that stress exerted on the rotor blade dovetail 5 can be reduced.
  • Another advantage obtained by forming a cut surface of the rotor blade dovetail 5 in the convex surface 13 b consisting of a plurality of flat surfaces is that machining is easier than when forming a cut surface of the rotor blade dovetail 5 in the spherical convex surface 16 or curved convex surface 10 .
  • an axial flow compressor having rotor blade dovetails that reduce an uneven contact with each wheel dovetail so as to level a load, exerted from the relevant rotor blade, that would otherwise become asymmetric between the forward direction and reverse direction of the rotational direction of the rotor blade and to thereby reduce high stress exerted on the rotor blade, and a gas turbine, can be realized.
  • the rotor blade dovetail 5 in the axial flow compressor according to a twenty-first embodiment of the present invention will be described with reference to FIG. 23 .
  • FIG. 23 partially illustrates the rotor blade dovetail 5 that secures the rotor blade 4 included in the axial flow compressor according to the twenty-first embodiment of the present invention; on an end surface 5 b of the rotor blade dovetail 5 on the downstream side of the inclined surface 11 , which is a flat surface, the flat surface 6 b is formed, which is a cut surface.
  • This embodiment described above uses a structure in which the flat surface 6 b , which is a cut surface formed by cutting part of the rotor blade dovetail 5 on the downstream side in the flow direction of a working fluid toward the maximum width part 11 c of the inclined surface 11 , is formed on the end surface 5 b of the rotor blade dovetail 5 on the upstream side of the inclined surface 11 , which is a flat surface. Therefore, a load exerted from the rotor blade 4 can be evened; the load would otherwise become asymmetric between the forward direction and reverse direction of the rotational direction of the rotor blade 4 . As a result, high stress exerted on the rotor blade 4 can be reduced.
  • the inclined surface 11 of the rotor blade dovetail 5 is a flat surface, so the weight of the rotor blade dovetail 5 is reduced by the amount of formation of the inclined surface 11 as a flat surface. This is advantageous in that stress exerted on the rotor blade dovetail 5 can be reduced.
  • an axial flow compressor having rotor blade dovetails that reduce an uneven contact with each wheel dovetail so as to level a load, exerted from the relevant rotor blade, that would otherwise become asymmetric between the forward direction and reverse direction of the rotational direction of the rotor blade and to thereby reduce high stress exerted on the rotor blade, and a gas turbine, can be realized.
  • the rotor blade dovetail 5 in the axial flow compressor according to a twenty-second embodiment of the present invention will be described with reference to FIG. 24 .
  • FIG. 24 partially illustrates the rotor blade dovetail 5 that secures the rotor blade 4 included in the axial flow compressor 1 according to the twenty-second embodiment of the present invention; on an end surface 5 b of the rotor blade dovetail 5 on the downstream side of the inclined surface 11 , which is a flat surface, the curved concave surface 9 b is formed, which is a cut surface.
  • This embodiment described above uses a structure in which the curved concave surface 9 b , which is a cut surface formed by cutting part of the rotor blade dovetail 5 on the downstream side in the flow direction of a working fluid toward the maximum width part 11 c of the inclined surface 11 , is formed on the end surface 5 b of the rotor blade dovetail 5 on the downstream side of the inclined surface 11 , which is a flat surface. Therefore, a load exerted from the rotor blade 4 can be evened; the load would otherwise become asymmetric between the forward direction and reverse direction of the rotational direction of the rotor blade 4 . As a result, high stress exerted on the rotor blade 4 can be reduced.
  • the inclined surface 11 of the rotor blade dovetail 5 is a flat surface, so the weight of the rotor blade dovetail 5 is reduced by the amount of formation of the inclined surface 11 as a flat surface. This is advantageous in that stress exerted on the rotor blade dovetail 5 can be reduced.
  • an axial flow compressor having rotor blade dovetails that reduce an uneven contact with each wheel dovetail so as to level a load, exerted from the relevant rotor blade, that would otherwise become asymmetric between the forward direction and reverse direction of the rotational direction of the rotor blade and to thereby reduce high stress exerted on the rotor blade, and a gas turbine, can be realized.
  • the rotor blade dovetail 5 in the axial flow compressor according to a twenty-third embodiment of the present invention will be described with reference to FIG. 25 .
  • FIG. 25 partially illustrates the rotor blade dovetail 5 that secures the rotor blade 4 included in the axial flow compressor according to the twenty-third embodiment of the present invention; on an end surface 5 b of the rotor blade dovetail 5 on the downstream side of the inclined surface 11 , which is a flat surface, the curved convex surface 10 b is formed, which is a cut surface.
  • This embodiment described above uses a structure in which the curved convex surface 10 b , which is a cut surface formed by cutting part of the rotor blade dovetail 5 on the downstream side in the flow direction of a working fluid toward the maximum width part 11 c of the inclined surface 11 , is formed on the end surface 5 b of the rotor blade dovetail 5 on the downstream side of the inclined surface 11 , which is a flat surface. Therefore, a load exerted from the rotor blade 4 can be evened; the load would otherwise become asymmetric between the forward direction and reverse direction of the rotational direction of the rotor blade 4 . As a result, high stress exerted on the rotor blade 4 can be reduced.
  • the inclined surface 11 of the rotor blade dovetail 5 is a flat surface, so the weight of the rotor blade dovetail 5 is reduced by the amount of formation of the inclined surface 11 as a flat surface. This is advantageous in that stress exerted on the rotor blade dovetail 5 can be reduced.
  • an axial flow compressor having rotor blade dovetails that reduce an uneven contact with each wheel dovetail so as to level a load, exerted from the relevant rotor blade, that would otherwise become asymmetric between the forward direction and reverse direction of the rotational direction of the rotor blade and to thereby reduce high stress exerted on the rotor blade, and a gas turbine, can be realized.
  • the rotor blade dovetail 5 in the axial flow compressor according to a twenty-fourth embodiment of the present invention will be described with reference to FIG. 26 .
  • FIG. 26 partially illustrates the rotor blade dovetail 5 that secures the rotor blade 4 included in the axial flow compressor according to the twenty-fourth embodiment of the present invention; on the end surface 5 b of the rotor blade dovetail 5 on the downstream side of the inclined surface 11 , which is a flat surface, the concave surface 12 b consisting of a plurality of flat surfaces, each being a cut surface, is formed.
  • This embodiment described above uses a structure in which the concave surface 12 b consisting of a plurality of flat surfaces, each of which is a cut surface formed by cutting part of the rotor blade dovetail 5 on the downstream side in the flow direction of a working fluid toward the maximum width part 11 c of the inclined surface 11 , is formed on the end surface 5 b of the rotor blade dovetail 5 on the downstream side of the inclined surface 11 , which is a flat surface. Therefore, a load exerted from the rotor blade 4 can be evened; the load would otherwise become asymmetric between the forward direction and reverse direction of the rotational direction of the rotor blade 4 . As a result, high stress exerted on the rotor blade 4 can be reduced.
  • the cut surface is the concave surface 12 b consisting of a plurality of flat surfaces, so the weight of the rotor blade dovetail 5 is reduced by the amount of formation of the concave surface 12 b .
  • This is advantageous in that stress exerted on the rotor blade dovetail 5 can be reduced.
  • Another advantage obtained by forming a cut surface of the rotor blade dovetail 5 in the concave surface 12 b consisting of a plurality of flat surfaces is that machining is easier than when forming a cut surface of the rotor blade dovetail 5 in the spherical concave surface 15 or curved concave surface 9 .
  • the inclined surface 11 of the rotor blade dovetail 5 is a flat surface, so the weight of the rotor blade dovetail 5 is reduced by the amount of formation of the inclined surface 11 as a flat surface. This is advantageous in that stress exerted on the rotor blade dovetail 5 can be reduced.
  • an axial flow compressor having rotor blade dovetails that reduce an uneven contact with each wheel dovetail so as to level a load, exerted from the relevant rotor blade, that would otherwise become asymmetric between the forward direction and reverse direction of the rotational direction of the rotor blade and to thereby reduce high stress exerted on the rotor blade, and a gas turbine, can be realized.
  • the rotor blade dovetail 5 in the axial flow compressor according to a twenty-fifth embodiment of the present invention will be described with reference to FIG. 27 .
  • FIG. 27 partially illustrates the rotor blade dovetail 5 that secures the rotor blade 4 included in the axial flow compressor according to the twenty-fifth embodiment of the present invention; on the end surface 5 b of the rotor blade dovetail 5 on the downstream side of the inclined surface 11 , which is a flat surface, the concave surface 13 b consisting of a plurality of flat surfaces, each being a cut surface, is formed.
  • This embodiment described above uses a structure in which the convex surface 13 b consisting of a plurality of flat surfaces, each of which is a cut surface formed by cutting part of the rotor blade dovetail 5 on the downstream side in the flow direction of a working fluid toward the maximum width part 11 c of the inclined surface 11 , is formed on the end surface 5 b of the rotor blade dovetail 5 on the downstream side of the inclined surface 11 , which is a flat surface. Therefore, a load exerted from the rotor blade 4 can be evened; the load would otherwise become asymmetric between the forward direction and reverse direction of the rotational direction of the rotor blade 4 . As a result, high stress exerted on the rotor blade 4 can be reduced.
  • the cut surface is the convex surface 13 b consisting of a plurality of flat surfaces, so the weight of the rotor blade dovetail 5 is reduced by the amount of formation of the convex surface 13 b .
  • This is advantageous in that stress exerted on the rotor blade dovetail 5 can be reduced.
  • Another advantage obtained by forming a cut surface of the rotor blade dovetail 5 in the convex surface 13 b consisting of a plurality of flat surfaces is that machining is easier than when forming a cut surface of the rotor blade dovetail 5 in the spherical convex surface 16 or curved convex surface 10 .
  • the inclined surface 11 of the rotor blade dovetail 5 is a flat surface, so the weight of the rotor blade dovetail 5 is reduced by the amount of formation of the inclined surface 11 as a flat surface. This is advantageous in that stress exerted on the rotor blade dovetail 5 can be reduced.
  • an axial flow compressor having rotor blade dovetails that reduce an uneven contact with each wheel dovetail so as to level a load, exerted from the relevant rotor blade, that would otherwise become asymmetric between the forward direction and reverse direction of the rotational direction of the rotor blade and to thereby reduce high stress exerted on the rotor blade, and a gas turbine, can be realized.
  • the rotor blade dovetail 5 in the axial flow compressor according to a twenty-sixth embodiment of the present invention will be described with reference to FIG. 28 .
  • FIG. 28 partially illustrates the rotor blade dovetail 5 that secures the rotor blade 4 included in the axial flow compressor according to the twenty-sixth embodiment of the present invention; on the end surface 5 a of the rotor blade dovetail 5 on the upstream side of the inclined surface 7 , which is a curved surface, the spherical concave surface 15 is formed, which is a cut surface; on the end surface 5 b of the rotor blade dovetail 5 on the downstream side of the inclined surface 7 , which is a curved surface, the spherical concave surface 15 b is formed, which is a cut surface.
  • This embodiment described above uses a structure in which the spherical concave surface 15 , which is a cut surface formed by cutting part of the rotor blade dovetail 5 on the upstream side in the flow direction of a working fluid toward the maximum width part 7 c of the inclined surface 7 , is formed on the end surface 5 a of the rotor blade dovetail 5 on the upstream side of the inclined surface 7 , which is a curved surface, and the spherical concave surface 15 b , which is a cut surface formed by cutting part of the rotor blade dovetail 5 on the downstream side in the flow direction of the working fluid toward the maximum width part 7 c of the inclined surface 7 , is also formed on the end surface 5 b of the rotor blade dovetail 5 on the downstream side of the inclined surface 7 .
  • the spherical concave surface 15 and spherical concave surface 15 b are respectively formed as cut surfaces on the end surface 5 a of the rotor blade dovetail 5 on the upstream side of the inclined surface 7 and the end surface 5 b on its downstream side, so the weight of the rotor blade dovetail 5 is reduced by the amount of formation of the spherical concave surface 15 and spherical concave surface 15 b .
  • This is advantageous in that stress exerted on the rotor blade dovetail 5 can be reduced.
  • This embodiment described above uses a structure in which the spherical concave surface 15 , which is a cut surface, is formed on the end surface 5 a of the rotor blade dovetail 5 on the upstream side of the inclined surface 7 , which is a curved surface, and the spherical concave surface 15 b , which is a cut surface formed, is also formed on the end surface 5 b of the rotor blade dovetail 5 on the downstream side of the inclined surface 7 , which is a curved surface, so an uneven contact with the wheel dovetail 14 can be greatly reduced on both the upstream side and downstream side of the rotor blade dovetail 5 .
  • the spherical concave surface 15 and spherical concave surface 15 b are respectively formed as cut surfaces on the end surface 5 a of the rotor blade dovetail 5 on the upstream side of the inclined surface 7 and the end surface 5 b on its downstream side, so the weight of the rotor blade dovetail 5 is reduced by the amount of formation of the spherical concave surface 15 and spherical concave surface 15 b .
  • This is advantageous in that stress exerted on the rotor blade dovetail 5 can be reduced.
  • an axial flow compressor having rotor blade dovetails that reduce an uneven contact with each wheel dovetail so as to level a load, exerted from the relevant rotor blade, that would otherwise become asymmetric between the forward direction and reverse direction of the rotational direction of the rotor blade and to thereby reduce high stress exerted on the rotor blade, and a gas turbine, can be realized.
  • the rotor blade dovetail 5 in the axial flow compressor according to a twenty-seventh embodiment of the present invention will be described with reference to FIG. 29 .
  • FIG. 29 partially illustrates the rotor blade dovetail 5 that secures the rotor blade 4 included in the axial flow compressor according to the twenty-seventh embodiment of the present invention
  • the spherical convex surface 16 is formed, which is a cut surface
  • the end surface 5 b of the rotor blade dovetail 5 on the downstream side of the inclined surface 7 which is a curved surface
  • the spherical convex surface 16 b is formed, which is a cut surface.
  • This embodiment described above uses a structure in which the spherical convex surface 16 , which is a cut surface formed by cutting part of the rotor blade dovetail 5 on the upstream side in the flow direction of a working fluid toward the maximum width part 7 c of the inclined surface 7 , is formed on the end surface 5 a of the rotor blade dovetail 5 on the upstream side of the inclined surface 7 , which is a curved surface, and the spherical convex surface 16 b , which is a cut surface formed by cutting part of the rotor blade dovetail 5 on the downstream side in the flow direction of the working fluid toward the maximum width part 7 c of the inclined surface 7 , is also formed on the end surface 5 b of the rotor blade dovetail 5 on the downstream side of the inclined surface 7 .
  • This embodiment described above uses a structure in which the spherical convex surface 16 , which is a cut surface, is formed on the end surface 5 a of the rotor blade dovetail 5 on the upstream side of the inclined surface 7 , which is a curved surface, and the spherical convex surface 16 b , which is a cut surface formed, is also formed on the end surface 5 b of the rotor blade dovetail 5 on the downstream side of the inclined surface 7 , which is a curved surface, so an uneven contact with the wheel dovetail 14 can be greatly reduced on both the upstream side and downstream side of the rotor blade dovetail 5 .
  • the spherical convex surface 16 and spherical convex surface 16 b are respectively formed as cut surfaces on the end surface 5 a of the rotor blade dovetail 5 on the upstream side of the inclined surface 7 and the end surface 5 b on its downstream side, so the weight of the rotor blade dovetail 5 is reduced by the amount of formation of the spherical convex surface 16 and spherical convex surface 16 b .
  • This is advantageous in that stress exerted on the rotor blade dovetail 5 can be reduced.
  • an axial flow compressor having rotor blade dovetails that reduce an uneven contact with each wheel dovetail so as to level a load, exerted from the relevant rotor blade, that would otherwise become asymmetric between the forward direction and reverse direction of the rotational direction of the rotor blade and to thereby reduce high stress exerted on the rotor blade, and a gas turbine, can be realized.
  • the rotor blade dovetail 5 in the axial flow compressor according to a twenty-eighth embodiment of the present invention will be described with reference to FIG. 30 .
  • FIG. 30 partially illustrates the rotor blade dovetail 5 that secures the rotor blade 4 included in the axial flow compressor according to the twenty-eighth embodiment of the present invention
  • the curved concave surface 9 is formed, which is a cut surface
  • the end surface 5 b of the rotor blade dovetail 5 on the downstream side of the inclined surface 7 which is a curved surface
  • the curved concave surface 9 b is formed, which is a cut surface.
  • This embodiment described above uses a structure in which the curved concave surface 9 , which is a cut surface formed by cutting part of the rotor blade dovetail 5 on the upstream side in the flow direction of a working fluid toward the maximum width part 7 c of the inclined surface 7 , is formed on the end surface 5 a of the rotor blade dovetail 5 on the upstream side of the inclined surface 7 , which is a curved surface, and the curved concave surface 9 b , which is a cut surface formed by cutting part of the rotor blade dovetail 5 on the downstream side in the flow direction of the working fluid toward the maximum width part 7 c of the inclined surface 7 , is also formed on the end surface 5 b of the rotor blade dovetail 5 on the downstream side of the inclined surface 7 .
  • the curved concave surface 9 and curved concave surface 9 b are respectively formed as cut surfaces on the end surface 5 a of the rotor blade dovetail 5 on the upstream side of the inclined surface 7 and the end surface 5 b on its downstream side, so the weight of the rotor blade dovetail 5 is reduced by the amount of formation of the curved concave surface 9 and curved concave surface 9 b .
  • This is advantageous in that stress exerted on the rotor blade dovetail 5 can be reduced.
  • an axial flow compressor having rotor blade dovetails that reduce an uneven contact with each wheel dovetail so as to level a load, exerted from the relevant rotor blade, that would otherwise become asymmetric between the forward direction and reverse direction of the rotational direction of the rotor blade and to thereby reduce high stress exerted on the rotor blade, and a gas turbine, can be realized.
  • the rotor blade dovetail 5 in the axial flow compressor according to a twenty-ninth embodiment of the present invention will be described with reference to FIG. 31 .
  • FIG. 31 partially illustrates the rotor blade dovetail 5 that secures the rotor blade 4 included in the axial flow compressor according to the twenty-ninth embodiment of the present invention
  • the curved convex surface 10 is formed, which is a cut surface
  • the end surface 5 b of the rotor blade dovetail 5 on the downstream side of the inclined surface 7 which is a curved surface
  • the curved convex surface 10 b is formed, which is a cut surface.
  • This embodiment described above uses a structure in which the curved convex surface 10 , which is a cut surface formed by cutting part of the rotor blade dovetail 5 on the upstream side in the flow direction of a working fluid toward the maximum width part 7 c of the inclined surface 7 , is formed on the end surface 5 a of the rotor blade dovetail 5 on the upstream side of the inclined surface 7 , which is a curved surface, and the curved convex surface 10 b , which is a cut surface formed by cutting part of the rotor blade dovetail 5 on the downstream side in the flow direction of the working fluid toward the maximum width part 7 c of the inclined surface 7 , is also formed on the end surface 5 b of the rotor blade dovetail 5 on the downstream side of the inclined surface 7 .
  • the curved convex surface 10 and curved convex surface 10 b are respectively formed as cut surfaces on the end surface 5 a of the rotor blade dovetail 5 on the upstream side of the inclined surface 7 and the end surface 5 b on its downstream side, so the weight of the rotor blade dovetail 5 is reduced by the amount of formation of the curved convex surface 10 and curved convex surface 10 b .
  • This is advantageous in that stress exerted on the rotor blade dovetail 5 can be reduced.
  • an axial flow compressor having rotor blade dovetails that reduce an uneven contact with each wheel dovetail so as to level a load, exerted from the relevant rotor blade, that would otherwise become asymmetric between the forward direction and reverse direction of the rotational direction of the rotor blade and to thereby reduce high stress exerted on the rotor blade, and a gas turbine, can be realized.
  • the rotor blade dovetail 5 in the axial flow compressor according to a thirtieth embodiment of the present invention will be described with reference to FIG. 32 .
  • FIG. 32 partially illustrates the rotor blade dovetail 5 that secures the rotor blade 4 included in the axial flow compressor according to the thirtieth embodiment of the present invention; on the end surface 5 a of the rotor blade dovetail 5 on the upstream side of the inclined surface 7 , which is a curved surface, the concave surface 12 consisting of a plurality of flat surfaces, each being a cut surface, is formed; on the end surface 5 b of the rotor blade dovetail 5 on the downstream side of the inclined surface 7 , which is a curved surface, the concave surface 12 b consisting of a plurality of flat surfaces, each being a cut surface, is formed.
  • This embodiment described above uses a structure in which the concave surface 12 consisting of a plurality of flat surfaces, each of which is a cut surface formed by cutting part of the rotor blade dovetail 5 on the upstream side in the flow direction of a working fluid toward the maximum width part 7 c of the inclined surface 7 , is formed on the end surface 5 a of the rotor blade dovetail 5 on the upstream side of the inclined surface 7 , which is a curved surface, and the concave surface 12 b consisting of a plurality of flat surfaces, each of which is a cut surface formed by cutting part of the rotor blade dovetail 5 on the downstream side in the flow direction of the working fluid toward the maximum width part 7 c of the inclined surface 7 , is also formed on the end surface 5 b of the rotor blade dovetail 5 on the downstream side of the inclined surface 7 .
  • the concave surface 12 and concave surface 12 b consisting of a plurality of flat surfaces are respectively formed as cut surfaces on the end surface 5 a of the rotor blade dovetail 5 on the upstream side of the inclined surface 7 and the end surface 5 b on its downstream side, so the weight of the rotor blade dovetail 5 is reduced by the amount of formation of the concave surface 12 and concave surface 12 b .
  • This is advantageous in that stress exerted on the rotor blade dovetail 5 can be reduced.
  • an axial flow compressor having rotor blade dovetails that reduce an uneven contact with each wheel dovetail so as to level a load, exerted from the relevant rotor blade, that would otherwise become asymmetric between the forward direction and reverse direction of the rotational direction of the rotor blade and to thereby reduce high stress exerted on the rotor blade, and a gas turbine, can be realized.
  • the rotor blade dovetail 5 in the axial flow compressor according to a thirty-first embodiment of the present invention will be described with reference to FIG. 33 .
  • FIG. 33 partially illustrates the rotor blade dovetail 5 that secures the rotor blade 4 included in the axial flow compressor according to the thirty-first embodiment of the present invention; on the end surface 5 a of the rotor blade dovetail 5 on the upstream side of the inclined surface 7 , which is a curved surface, the convex surface 13 consisting of a plurality of flat surfaces, each being a cut surface, is formed; on the end surface 5 b of the rotor blade dovetail 5 on the downstream side of the inclined surface 7 , which is a curved surface, the convex surface 13 b consisting of a plurality of flat surfaces, each being a cut surface, is formed.
  • This embodiment described above uses a structure in which the convex surface 13 consisting of a plurality of flat surfaces, each of which is a cut surface formed by cutting part of the rotor blade dovetail 5 on the upstream side in the flow direction of a working fluid toward the maximum width part 7 c of the inclined surface 7 , is formed on the end surface 5 a of the rotor blade dovetail 5 on the upstream side of the inclined surface 7 , which is a curved surface, and the convex surface 13 b consisting of a plurality of flat surfaces, each of which is a cut surface formed by cutting part of the rotor blade dovetail 5 on the downstream side in the flow direction of the working fluid toward the maximum width part 7 c of the inclined surface 7 , is also formed on the end surface 5 b of the rotor blade dovetail 5 on the downstream side of the inclined surface 7 .
  • the convex surface 13 and convex surface 13 b consisting of a plurality of flat surfaces are respectively formed as cut surfaces on the end surface 5 a of the rotor blade dovetail 5 on the upstream side of the inclined surface 7 and the end surface 5 b on its downstream side, so the weight of the rotor blade dovetail 5 is reduced by the amount of formation of the convex surface 13 and convex surface 13 b .
  • This is advantageous in that stress exerted on the rotor blade dovetail 5 can be reduced.
  • an axial flow compressor having rotor blade dovetails that reduce an uneven contact with each wheel dovetail so as to level a load, exerted from the relevant rotor blade, that would otherwise become asymmetric between the forward direction and reverse direction of the rotational direction of the rotor blade and to thereby reduce high stress exerted on the rotor blade, and a gas turbine, can be realized.
  • the rotor blade dovetail 5 in the axial flow compressor according to a thirty-second embodiment of the present invention will be described with reference to FIG. 34 .
  • FIG. 34 partially illustrates the rotor blade dovetail 5 that secures the rotor blade 4 included in the axial flow compressor according to the thirty-second embodiment of the present invention; on an end surface 5 a of the rotor blade dovetail 5 on the upstream side of the inclined surface 11 , which is a flat surface, the flat surface 6 is formed, which is a cut surface; on an end surface 5 b of the rotor blade dovetail 5 on the downstream side of the inclined surface 11 , which is a flat surface, the flat surface 6 b is formed, which is a cut surface.
  • This embodiment described above uses a structure in which the flat surface 6 , which is a cut surface formed by cutting part of the rotor blade dovetail 5 on the upstream side in the flow direction of a working fluid toward the maximum width part 11 c of the inclined surface 11 , is formed on the end surface 5 a of the rotor blade dovetail 5 on the upstream side of the inclined surface 11 , which is a flat surface, and the flat surface 6 b , which is a cut surface formed by cutting part of the rotor blade dovetail 5 on the downstream side in the flow direction of the working fluid toward the maximum width part 11 c of the inclined surface 11 , is also formed on the end surface 5 b of the rotor blade dovetail 5 on the downstream side of the inclined surface 11 .
  • the flat surface 6 and flat surface 6 b are respectively formed as cut surfaces on the end surface 5 a of the rotor blade dovetail 5 on the upstream side of the inclined surface 11 and the end surface 5 b on its downstream side, so the weight of the rotor blade dovetail 5 is reduced by the amount of formation of the flat surface 6 and flat surface 6 b .
  • This is advantageous in that stress exerted on the rotor blade dovetail 5 can be reduced.
  • the inclined surface 11 of the rotor blade dovetail 5 is a flat surface, so the weight of the rotor blade dovetail 5 is reduced by the amount of formation of the inclined surface 11 as a flat surface. This is advantageous in that stress exerted on the rotor blade dovetail 5 can be reduced.
  • an axial flow compressor having rotor blade dovetails that reduce an uneven contact with each wheel dovetail so as to level a load, exerted from the relevant rotor blade, that would otherwise become asymmetric between the forward direction and reverse direction of the rotational direction of the rotor blade and to thereby reduce high stress exerted on the rotor blade, and a gas turbine, can be realized.
  • the rotor blade dovetail 5 in the axial flow compressor according to a thirty-third embodiment of the present invention will be described with reference to FIG. 35 .
  • FIG. 35 partially illustrates the rotor blade dovetail 5 that secures the rotor blade 4 included in the axial flow compressor according to the thirty-third embodiment of the present invention; on an end surface 5 a of the rotor blade dovetail 5 on the upstream side of the inclined surface 11 , which is a flat surface, the curved concave surface 9 is formed, which is a cut surface; on an end surface 5 b of the rotor blade dovetail 5 on the downstream side of the inclined surface 11 , which is a flat surface, the curved concave surface 9 b is formed, which is a cut surface.
  • This embodiment described above uses a structure in which the curved concave surface 9 , which is a cut surface formed by cutting part of the rotor blade dovetail 5 on the upstream side in the flow direction of a working fluid toward the maximum width part 11 c of the inclined surface 11 , is formed on the end surface 5 a of the rotor blade dovetail 5 on the upstream side of the inclined surface 11 , which is a flat surface, and the curved concave surface 9 b , which is a cut surface formed by cutting part of the rotor blade dovetail 5 on the downstream side in the flow direction of the working fluid toward the maximum width part 11 c of the inclined surface 11 , is also formed on the end surface 5 b of the rotor blade dovetail 5 on the downstream side of the inclined surface 11 .
  • the curved concave surface 9 and curved concave surface 9 b are respectively formed as cut surfaces on the end surface 5 a of the rotor blade dovetail 5 on the upstream side of the inclined surface 11 and the end surface 5 b on its downstream side, so the weight of the rotor blade dovetail 5 is reduced by the amount of formation of the curved concave surface 9 and curved concave surface 9 b .
  • This is advantageous in that stress exerted on the rotor blade dovetail 5 can be reduced.
  • the inclined surface 11 of the rotor blade dovetail 5 is a flat surface, so the weight of the rotor blade dovetail 5 is reduced by the amount of formation of the inclined surface 11 as a flat surface. This is advantageous in that stress exerted on the rotor blade dovetail 5 can be reduced.
  • an axial flow compressor having rotor blade dovetails that reduce an uneven contact with each wheel dovetail so as to level a load, exerted from the relevant rotor blade, that would otherwise become asymmetric between the forward direction and reverse direction of the rotational direction of the rotor blade and to thereby reduce high stress exerted on the rotor blade, and a gas turbine, can be realized.
  • the rotor blade dovetail 5 in the axial flow compressor according to a thirty-fourth embodiment of the present invention will be described with reference to FIG. 36 .
  • FIG. 36 partially illustrates the rotor blade dovetail 5 that secures the rotor blade 4 included in the axial flow compressor according to the thirty-fourth embodiment of the present invention; on an end surface 5 a of the rotor blade dovetail 5 on the upstream side of the inclined surface 11 , which is a flat surface, the curved convex surface 10 is formed, which is a cut surface;
  • the curved convex surface 10 b is formed, which is a cut surface.
  • This embodiment described above uses a structure in which the curved convex surface 10 , which is a cut surface formed by cutting part of the rotor blade dovetail 5 on the upstream side in the flow direction of a working fluid toward the maximum width part 11 c of the inclined surface 11 , is formed on the end surface 5 a of the rotor blade dovetail 5 on the upstream side of the inclined surface 11 , which is a flat surface, and the curved convex surface 10 b , which is a cut surface formed by cutting part of the rotor blade dovetail 5 on the downstream side in the flow direction of the working fluid toward the maximum width part 11 c of the inclined surface 11 , is also formed on the end surface 5 b of the rotor blade dovetail 5 on the downstream side of the inclined surface 11 .
  • the curved convex surface 10 and curved convex surface 10 b are respectively formed as cut surfaces on the end surface 5 a of the rotor blade dovetail 5 on the upstream side of the inclined surface 11 and the end surface 5 b on its downstream side, so the weight of the rotor blade dovetail 5 is reduced by the amount of formation of the curved convex surface 10 and curved convex surface 10 b .
  • This is advantageous in that stress exerted on the rotor blade dovetail 5 can be reduced.
  • the inclined surface 11 of the rotor blade dovetail 5 is a flat surface, so the weight of the rotor blade dovetail 5 is reduced by the amount of formation of the inclined surface 11 as a flat surface. This is advantageous in that stress exerted on the rotor blade dovetail 5 can be reduced.
  • an axial flow compressor having rotor blade dovetails that reduce an uneven contact with each wheel dovetail so as to level a load, exerted from the relevant rotor blade, that would otherwise become asymmetric between the forward direction and reverse direction of the rotational direction of the rotor blade and to thereby reduce high stress exerted on the rotor blade, and a gas turbine, can be realized.
  • the rotor blade dovetail 5 in the axial flow compressor according to a thirty-fifth embodiment of the present invention will be described with reference to FIG. 37 .
  • FIG. 37 partially illustrates the rotor blade dovetail 5 that secures the rotor blade 4 included in the axial flow compressor according to the thirty-fifth embodiment of the present invention; on the end surface 5 a of the rotor blade dovetail 5 on the upstream side of the inclined surface 11 , which is a flat surface, the concave surface 12 consisting of a plurality of flat surfaces, each being a cut surface, is formed; on the end surface 5 b of the rotor blade dovetail 5 on the downstream side of the inclined surface 11 , which is a flat surface, the concave surface 12 b consisting of a plurality of flat surfaces, each being a cut surface, is formed.
  • This embodiment described above uses a structure in which the concave surface 12 consisting of a plurality of flat surfaces, each of which is a cut surface formed by cutting part of the rotor blade dovetail 5 on the upstream side in the flow direction of a working fluid toward the maximum width part 11 c of the inclined surface 11 , is formed on the end surface 5 a of the rotor blade dovetail 5 on the upstream side of the inclined surface 11 , which is a flat surface, and the concave surface 12 b consisting of a plurality of flat surfaces, each of which is a cut surface formed by cutting part of the rotor blade dovetail 5 on the downstream side in the flow direction of the working fluid toward the maximum width part 11 c of the inclined surface 11 , is also formed on the end surface 5 b of the rotor blade dovetail 5 on the downstream side of the inclined surface 11 .
  • the concave surface 12 and concave surface 12 b consisting of a plurality of flat surfaces are respectively formed as cut surfaces on the end surface 5 a of the rotor blade dovetail 5 on the upstream side of the inclined surface 11 and the end surface 5 b on its downstream side, so the weight of the rotor blade dovetail 5 is reduced by the amount of formation of the concave surface 12 and concave surface 12 b .
  • This is advantageous in that stress exerted on the rotor blade dovetail 5 can be reduced.
  • the inclined surface 11 of the rotor blade dovetail 5 is a flat surface, so the weight of the rotor blade dovetail 5 is reduced by the amount of formation of the inclined surface 11 as a flat surface. This is advantageous in that stress exerted on the rotor blade dovetail 5 can be reduced.
  • an axial flow compressor having rotor blade dovetails that reduce an uneven contact with each wheel dovetail so as to level a load, exerted from the relevant rotor blade, that would otherwise become asymmetric between the forward direction and reverse direction of the rotational direction of the rotor blade and to thereby reduce high stress exerted on the rotor blade, and a gas turbine, can be realized.
  • the rotor blade dovetail 5 in the axial flow compressor according to a thirty-sixth embodiment of the present invention will be described with reference to FIG. 38 .
  • FIG. 38 partially illustrates the rotor blade dovetail 5 that secures the rotor blade 4 included in the axial flow compressor according to the thirty-sixth embodiment of the present invention; on the end surface 5 a of the rotor blade dovetail 5 on the upstream side of the inclined surface 11 , which is a flat surface, the convex surface 13 consisting of a plurality of flat surfaces, each being a cut surface, is formed; on the end surface 5 b of the rotor blade dovetail 5 on the downstream side of the inclined surface 11 , which is a flat surface, the convex surface 13 b consisting of a plurality of flat surfaces, each being a cut surface, is formed.
  • This embodiment described above uses a structure in which the convex surface 13 consisting of a plurality of flat surfaces, each of which is a cut surface formed by cutting part of the rotor blade dovetail 5 on the upstream side in the flow direction of a working fluid toward the maximum width part 11 c of the inclined surface 11 , is formed on the end surface 5 a of the rotor blade dovetail 5 on the upstream side of the inclined surface 11 , which is a flat surface, and the convex surface 13 b consisting of a plurality of flat surfaces, each of which is a cut surface formed by cutting part of the rotor blade dovetail 5 on the downstream side in the flow direction of the working fluid toward the maximum width part 11 c of the inclined surface 11 , is also formed on the end surface 5 b of the rotor blade dovetail 5 on the downstream side of the inclined surface 11 .
  • the convex surface 13 and convex surface 13 b consisting of a plurality of flat surfaces are respectively formed as cut surfaces on the end surface 5 a of the rotor blade dovetail 5 on the upstream side of the inclined surface 11 and the end surface 5 b on its downstream side, so the weight of the rotor blade dovetail 5 is reduced by the amount of formation of the convex surface 13 and convex surface 13 b .
  • This is advantageous in that stress exerted on the rotor blade dovetail 5 can be reduced.
  • the inclined surface 11 of the rotor blade dovetail 5 is a flat surface, so the weight of the rotor blade dovetail 5 is reduced by the amount of formation of the inclined surface 11 as a flat surface. This is advantageous in that stress exerted on the rotor blade dovetail 5 can be reduced.
  • a range in which the above cut surfaces are formed on the end surfaces 5 a and 5 b of the inclined surfaces 7 and 11 of the rotor blade dovetail 5 is a portion, of the rotor blade dovetail 5 , that corresponds to a range in which stress at a certain level or higher is exerted from the rotor blade dovetail 5 to the wheel dovetail 14 .
  • stress exerted from the rotor blade dovetail to the wheel dovetail may be increased to a designed allowable stress or higher.
  • any one of the above cut surfaces is formed in part of the rotor blade dovetail 5 , the part being a range, of the rotor blade dovetail 5 , that corresponds to a range, in the wheel dovetail 14 , in which stress at a certain level or higher is exerted from the rotor blade dovetail 5 to the wheel dovetail 14
  • the material of the rotor blade dovetail 5 may be casted so that the rotor blade dovetail 5 is formed in a state in which it has a certain cut surface in advance.
  • the rotor blade dovetail 5 may be cut by, for example, machining or electric discharge machining.
  • an axial flow compressor having rotor blade dovetails that reduce an uneven contact with each wheel dovetail so as to level a load, exerted from the relevant rotor blade, that would otherwise become asymmetric between the forward direction and reverse direction of the rotational direction of the rotor blade and to thereby reduce high stress exerted on the rotor blade, and a gas turbine, can be realized.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Architecture (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Structures Of Non-Positive Displacement Pumps (AREA)
US14/813,418 2014-08-01 2015-07-30 Axial flow compressor and gas turbine equipped with axial flow compressor Abandoned US20160032739A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2014157405A JP2016035209A (ja) 2014-08-01 2014-08-01 軸流圧縮機、及び軸流圧縮機を備えたガスタービン
JP2014-157405 2014-08-01

Publications (1)

Publication Number Publication Date
US20160032739A1 true US20160032739A1 (en) 2016-02-04

Family

ID=54062614

Family Applications (1)

Application Number Title Priority Date Filing Date
US14/813,418 Abandoned US20160032739A1 (en) 2014-08-01 2015-07-30 Axial flow compressor and gas turbine equipped with axial flow compressor

Country Status (4)

Country Link
US (1) US20160032739A1 (de)
EP (1) EP2985416A1 (de)
JP (1) JP2016035209A (de)
CN (1) CN105317739A (de)

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20190063234A1 (en) * 2017-08-18 2019-02-28 Safran Aircraft Engines Turbine for a turbine engine
US20190098276A1 (en) * 2017-09-27 2019-03-28 Facebook Technologies, Llc 3-d 360 degree depth projector
CN109915412A (zh) * 2019-03-07 2019-06-21 北航（四川）西部国际创新港科技有限公司 具有非对称端壁的单级轴流高压压气机
EP3594450A1 (de) * 2018-07-09 2020-01-15 Rolls-Royce plc Schaufel für ein gasturbinentriebwerk
US11073031B2 (en) * 2018-01-17 2021-07-27 Rolls-Royce Plc Blade for a gas turbine engine
US20230102240A1 (en) * 2020-02-19 2023-03-30 Mitsubishi Heavy Industries, Ltd. Turbine blade and turbine
US11814984B2 (en) 2019-06-12 2023-11-14 Mitsubishi Heavy Industries, Ltd. Rotor and compressor

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP6622176B2 (ja) * 2016-11-30 2019-12-18 三菱重工業株式会社 ガスタービン用高温部品及びガスタービン
GB201901683D0 (en) * 2019-02-07 2019-03-27 Rolls Royce Plc Blade for a gas turbine engine
CN110052042B (zh) * 2019-05-22 2024-03-26 张洋 圆角燕尾榫与燕尾卯组件及其拼装、拆解方法

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20090297351A1 (en) * 2008-05-28 2009-12-03 General Electric Company Compressor rotor blade undercut
US9151167B2 (en) * 2012-02-10 2015-10-06 General Electric Company Turbine assembly

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1997049921A1 (de) * 1996-06-21 1997-12-31 Siemens Aktiengesellschaft Rotor für eine turbomaschine mit in nuten anbringbaren schaufeln sowie schaufel für einen rotor
DE19705323A1 (de) * 1997-02-12 1998-08-27 Siemens Ag Reduzierung von lokalen Spannungen in Schaufelfußnuten
US6846159B2 (en) * 2002-04-16 2005-01-25 United Technologies Corporation Chamfered attachment for a bladed rotor
US7594799B2 (en) 2006-09-13 2009-09-29 General Electric Company Undercut fillet radius for blade dovetails
US20090208339A1 (en) * 2008-02-15 2009-08-20 United Technologies Corporation Blade root stress relief
US9810077B2 (en) * 2012-01-31 2017-11-07 United Technologies Corporation Fan blade attachment of gas turbine engine

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20090297351A1 (en) * 2008-05-28 2009-12-03 General Electric Company Compressor rotor blade undercut
US9151167B2 (en) * 2012-02-10 2015-10-06 General Electric Company Turbine assembly

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20190063234A1 (en) * 2017-08-18 2019-02-28 Safran Aircraft Engines Turbine for a turbine engine
US10914184B2 (en) * 2017-08-18 2021-02-09 Safran Aircraft Engines Turbine for a turbine engine
US20190098276A1 (en) * 2017-09-27 2019-03-28 Facebook Technologies, Llc 3-d 360 degree depth projector
US11073031B2 (en) * 2018-01-17 2021-07-27 Rolls-Royce Plc Blade for a gas turbine engine
EP3594450A1 (de) * 2018-07-09 2020-01-15 Rolls-Royce plc Schaufel für ein gasturbinentriebwerk
CN109915412A (zh) * 2019-03-07 2019-06-21 北航（四川）西部国际创新港科技有限公司 具有非对称端壁的单级轴流高压压气机
US11814984B2 (en) 2019-06-12 2023-11-14 Mitsubishi Heavy Industries, Ltd. Rotor and compressor
US20230102240A1 (en) * 2020-02-19 2023-03-30 Mitsubishi Heavy Industries, Ltd. Turbine blade and turbine
US11867088B2 (en) * 2020-02-19 2024-01-09 Mitsubishi Heavy Industries, Ltd. Turbine blade and turbine

Also Published As

Publication number Publication date
JP2016035209A (ja) 2016-03-17
CN105317739A (zh) 2016-02-10
EP2985416A1 (de) 2016-02-17

Similar Documents

Publication Publication Date Title
US20160032739A1 (en) Axial flow compressor and gas turbine equipped with axial flow compressor
JP7034587B2 (ja) シュラウド付きタービン・ロータ・ブレード
US8721287B2 (en) Compressor impeller blade with variable elliptic connection
US9506347B2 (en) Compressor blade for gas turbine engine
US10190423B2 (en) Shrouded blade for a gas turbine engine
US9822647B2 (en) High chord bucket with dual part span shrouds and curved dovetail
US20100054946A1 (en) Compressor blade with forward sweep and dihedral
RU2541078C2 (ru) Турбинная лопатка и способ ее изготовления
US9109455B2 (en) Turbomachine blade tip shroud
US9879542B2 (en) Platform with curved edges adjacent suction side of airfoil
US20140150454A1 (en) Turbine blade apparatus
EP3144480A1 (de) Ausnehmung im laufschaufelfuss zur spannungsverminderung
EP4130430A1 (de) Integrierter beschaufelter rotor
US20150098832A1 (en) Method and system for relieving turbine rotor blade dovetail stress
CA2897652C (en) Outer shroud with gusset
EP3486433A1 (de) Labyrinthdichtung mit unterschiedlichen zahnhöhen
US20160076385A1 (en) Turbomachine blade tip shroud
EP2669478A1 (de) Verdichter
US11073031B2 (en) Blade for a gas turbine engine
US20200011188A1 (en) Blade for a gas turbine engine
JP5039676B2 (ja) 回転体ボルト締結構造及び回転機械
US10001134B2 (en) Rotor disc
WO2016148691A1 (en) Shrouded turbine airfoil with knife edge seal

Legal Events

Date Code Title Description
AS Assignment

Owner name: MITSUBISHI HITACHI POWER SYSTEMS, LTD., JAPAN

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:SEKIHARA, MASARU;TAKAHASHI, YASUO;REEL/FRAME:036216/0198

Effective date: 20150702

STCB Information on status: application discontinuation

Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION